Apparatus for the deposition of high dielectric constant films

ABSTRACT

An integrated deposition system is described that is capable of vaporizing low vapor pressure liquid precursors and conveying the vapor to a processing region to fabricate advanced integrated circuits. The integrated deposition system includes a heated exhaust system, a remote plasma generator, a processing chamber, a liquid delivery system, and a computer control module that together create a commercially viable and production worthy system for depositing high capacity dielectric materials from low vapor pressure precursors.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is divisional of U.S. patent application Ser. No.11/356,725, filed Feb. 17, 2006, which is continuation of U.S. patentapplication Ser. No. 10/251,715, filed Sep. 20, 2002 which is acontinuation-in-part of U.S. patent application Ser. No. 09/179,921,filed Oct. 27, 1998, now U.S. Pat. No. 6,454,860, all of which areincorporated by reference in their entireties.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to an apparatus for the vaporization of liquidprecursors and the controlled delivery of those precursors to form filmson suitable substrates. More specifically, this invention concerns anapparatus for the deposition of a high dielectric constant film on asilicon wafer to make integrated circuits useful in the manufacture ofadvanced dynamic random access memory modules and other semiconductordevices.

DESCRIPTION OF THE RELATED ART

As the dimensions of the transistors continue to decrease, the continueduse of silicon dioxide as a dielectric gate material is problematic. Thefundamental problem is the need to keep the capacitance of the gate highwhile the area of the gate is shrinking faster than the thickness of thegate dielectric stack. The capacitance C of the gate is given byC=kε_(o)A/d where A is the area of the gate, d is the thickness of thedielectric stack, k is the dielectric constant, and ε_(o) is thepermittivity of free space. To ensure higher gate oxide capacitance, thesilicon dioxide layer thickness has been decreased to less than 2nanometers and future generations may require a further reduction below1.0 nanometer. Since the dominant transport mechanism for silicondioxide (SiO₂) films less than approximately 3 nanometers thick is bydirect tunneling of electrons or holes, the leakage current densityincreases exponentially with decreasing thickness. A typical leakagecurrent density for 1.5 nanometers thick SiO₂ at 1 V is about 1 A/cm².But, as the SiO₂ thickness approaches 1 nanometer, the leakage-currentdensity approaches an unacceptable 100 A/cm² at the same operatingvoltage.

Consequently, there is a need for an alternative gate dielectricmaterial that can be used in a large enough physical thickness to reducecurrent leakage density and still provide a high gate capacitance. Inorder to achieve this, the alternative gate dielectric material musthave a dielectric constant that is higher than that of silicon dioxide.Typically, the thickness of such an alternative dielectric materiallayer is expressed in terms of the equivalent oxide thickness (EOT).Thus, the equivalent oxide thickness (EOT) of an alternative dielectriclayer in a particular capacitor is the thickness that the alternativedielectric layer would have if its dielectric constant were that ofsilicon dioxide.

Another consideration in selecting an alternative dielectric material isthe mobility of electrons in the transistor channel. The materialselected for the dielectric film effects the mobility of the carriers inthe transistor channel, thereby affecting overall transistorperformance. Thus, it is desirable to find an alternative dielectricmaterial for which the mobility of carriers in the transistor channel isequivalent to or higher than that for silicon dioxide gate dielectricfilms. For future generation transistors, a peak mobility of 400 cm²/V.sor greater is desirable.

This drive toward smaller transistors is driven by the desire for moreintegrated circuits (ICs) on a semiconductor die. Manufacturers areinterested in replacing today's 64 megabit DRAM with memory devices inthe range of 256 megabit, 1 gigabit, and higher. This need for more ICson the same or smaller substrate footprint makes it necessary to replaceconventional dielectric films, such as SiO₂, with dielectric filmshaving higher dielectric constants (“High k” films).

High k films are desirable because their higher dielectric constantsmean they provide higher capacitance that enables closer spacing ofdevices without electrical interference. Such closer spacing canincrease transistor density. In addition, capacitor size can be reducedbecause capacitors containing high dielectric constant materials, suchas tantalum oxide (Ta₂O₅), usually have much larger capacitancedensities than standard SiO₂—Si₃N₄—SiO₂ stack capacitors. In fact,tantalum oxide has a relative dielectric constant more than six timesthat of SiO₂. Thus, High k materials such as tantalum oxide are becomingthe materials of choice in IC fabrication.

One common method of forming a tantalum oxide film is to vaporize aliquid tantalum precursor and then deliver the tantalum vapor to adeposition chamber. FIG. 1, which is a graph of Vapor Pressure (Torr)vs. Temperature (C) of various compositions, graphically illustrates thelarge variation among the vapor pressures of tantalum precursors andother representative prior-art precursors for other semiconductorrelated processes. For example, at 100 C and 1 atm TAT-DMAE has about0.3 Torr vapor pressure while TAETO has about 0.03 Torr vapor pressure.The vapor pressures for tantalum precursors are remarkably lower thanthose of precursors typically used in prior art vapor delivery systems.Again referring to FIGS. 1, at 100 C and 1 atm, TEOS (Tetra Ethyl OrthoSilicate), which is commonly used in chemical vapor deposition processesto form SiO₂ films and is supplied by several prior art vapor deliverysystems, has a vapor pressure of almost 100 Torr. As a result of thevast difference in vapor pressure illustrated by TAETO and TEOS, priorart vapor delivery systems do not encounter and do not provide solutionsto many of the challenges resulting from the use of very low vaporpressure precursors such as TAETO and TAT-DMAE.

Prior art vapor delivery systems commonly use an integrated liquid flowcontroller and vaporizer without a positive liquid shut-off valve. Sucha configuration, when used with low vapor pressure tantalum precursors,can lead to problems stabilizing the tantalum vapor output anddifficulty achieving the constant, repeatable tantalum vapor outputdesired in semiconductor device fabrication. Prior art delivery systemsfor TEOS and other relatively high vapor pressure materials allow forthe flow controller and vaporizer to be separated by a considerabledistance or attach no significance to the distance between vaporizer andliquid flow meter. Positioning the vaporizer and flow meter according toprior art systems fails to adequately control precursor vapor in thecase of low vapor pressure precursors.

Previous delivery systems also have cleaning systems that are intendedfor use with higher vapor pressure precursors whose residuals can beadequately removed (“purged”) by applying low pressure or “pumping-down”the lines while flowing a gas like nitrogen that is inert, relative tothese materials. Purging techniques such as these fail with tantalumsystems because the residual tantalum precursor has such a low vaporpressure that to remove it a system must introduce a solvent, such asisopropyl alcohol, ethanol, hexane, or methanol, into both thevaporization system and supply lines.

Previous vapor delivery systems avoided precursor vapor condensation byheating the delivery lines. These heating systems usually resorted to aflexible resistive heater that was wrapped around and held in directcontact with the line and then insulated. Since such systems typicallyoperated with precursor materials having a wide temperature range withinwhich the precursor remained vaporous, they did not need to sample thetemperature of the heated line in as many locations. Typically, a singlethermocouple would be used to represent the temperature of pipingsections as long as four to six feet. Unfortunately, since the object ofthese large scale temperature control systems is to heat and monitor anaverage temperature of a large section of piping, these systems lack theability to specifically control a single, smaller section of the vaporpiping. An additional detriment is that these systems generally havevery low efficiency when higher line temperatures are desired.

Vaporized tantalum delivery systems need to maintain the tantalum vaporabove the vaporization temperature but below the decompositiontemperature for a given tantalum precursor. Thus, once formed, thevaporous tantalum must be maintained at elevated temperatures betweenabout 130° C. and 190° C. for TAT-DMAE and between about 150° C. and220° C. for TAETO. Because of the relatively high temperatures neededand the narrow temperature band available to low vapor pressureprecursors such as TAT-DMAE and TAETO, tantalum and other low vaporpressure liquid delivery systems would benefit from vapor delivery linetemperature controls and methods that can achieve and efficientlyprovide the higher temperatures and greater temperature control neededfor tantalum vapor delivery. Additionally, more precise temperaturecontrols are needed since the usable temperature range of vaporized lowpressure liquids is smaller than the usable range of prior art liquids.Because higher temperature vapor delivery is needed, tantalum deliverysystems would benefit from designs that minimize the length of heatedvapor delivery lines. Minimizing the length of lines requiring heatingnot only reduces the overall system complexity but also decreases thefootprint or overall size of the system.

Current methods of tantalum oxide deposition use reaction rate limitedchemical vapor deposition techniques. In reaction rate limiteddeposition processes, the deposition rate achieved is largely influencedby the temperature of the reaction environment. Existing chemical vapordeposition reactors do not sufficiently address the thermal losses fromthe substrate onto which the tantalum film is to be formed and theinternal chamber components such as the gas distribution showerhead.Such thermal losses result in a non-uniform thickness of depositedtantalum and this non-uniformity is one barrier to having commerciallyviable tantalum oxide film formation techniques. Also, a commerciallyviable tantalum deposition requires a viable, in-situ cleaning processthat can remove tantalum deposition formed on internal chambercomponents without harm to these components.

Thus, there is a need for a deposition apparatus that can delivervaporized, measured High k precursors, such as tantalum, hafnium, orzirconium precursors, that have been adequately mixed with process gasesto a reaction chamber that provides a controlled deposition environmentthat overcomes the shortcomings of the previous systems.

BRIEF SUMMARY OF THE INVENTION

This invention provides an apparatus for depositing a film, particularlya High k film. To deliver High k films better, an embodiment of theapparatus has a shortened vapor delivery system in which the conduitsfrom the vapor delivery system to the processing region are segmentedinto multiple individually heated and controlled sections that allowprecise vapor temperature control. Additionally, an embodiment of theapparatus segments the gas and liquid delivery systems into separate butsimilar individually heated and controlled sections to improve vaportemperature control. Further, an embodiment of the apparatus segmentsthe chamber assembly into individually controlled sections that areheated to allow more precise vapor temperature control, to reduce vapordeposition on the chamber itself, and to reduce chamber assemblytemperature where warranted. Additionally, an embodiment of theinvention allows for the simultaneous delivery of two separate High ksources, thus allowing for multi-component film deposition.

In one embodiment the apparatus includes: a chamber assembly including achamber body and a processing region; a first vaporizer; and a vapordelivery system connecting said first vaporizer and said processingregion with a first vapor path of less than approximately three feetfrom said first vaporizer through said vapor delivery system to saidprocessing region.

In another embodiment the apparatus includes: a chamber assemblyincluding a chamber body, a chamber lid, and a processing region; afirst vaporizer; a vapor delivery system connecting the first vaporizerto the processing region, the vapor delivery system including: a vapordelivery manifold wherein: the vapor delivery manifold is mounted on thechamber lid; the first vaporizer is mounted on the vapor deliverymanifold; and the vapor delivery manifold connects the first vaporizerto the processing region.

Yet another embodiment of the apparatus includes: a chamber assemblyincluding a chamber body, a chamber lid, and a processing region; afirst vaporizer; a vapor delivery system connecting the first vaporizerto the processing region, the vapor delivery system including: a vapordelivery manifold wherein: the vapor delivery manifold is mounted on thechamber lid; the first vaporizer is mounted on the vapor deliverymanifold; and the vapor delivery manifold connects the first vaporizerto the processing region; a plurality of heated zones; a heater inthermal contact with each of the heated zones; a thermocouple in thermalcontact with each of the heated zones; and a plurality of temperaturecontrollers, wherein one of the plurality of temperature controllers isin communication with each of the heaters and thermocouples to maintainthe heated zones at a first target temperature.

Another embodiment of the apparatus includes: a chamber assemblyincluding a chamber body, a chamber lid, and a processing region; afirst vaporizer; a second vaporizer; a vapor delivery system connectingthe first and second vaporizers to the processing region, the vapordelivery system including: a vapor delivery manifold wherein: the vapordelivery manifold is mounted on the chamber lid; the first and secondvaporizers are mounted on the vapor delivery manifold; and the vapordelivery manifold connects the first and second vaporizers to theprocessing region; a plurality of heated zones; a heater in thermalcontact with each of the heated zones; a thermocouple in thermal contactwith each of the heated zones; and a plurality of temperaturecontrollers, wherein one of the plurality of temperature controllers isin communication with each of the heaters and thermocouples to maintainthe heated zones at a first target temperature.

An additional embodiment of the apparatus includes a double containmentline for delivering a precursor to a chamber assembly, with the doublecontainment line including: an outer tube including a first flexiblesection; an inner tube including a second flexible section, wherein theinner tube passes through the outer tube to create an annular space, andwherein the second flexible section is primarily within the firstflexible section; a plurality of annular plugs that are positioned toenclose that portion of the annular space that lies between the firstand second flexible sections to create an annular volume; and a gas,wherein the gas fills the annular volume and creates a pressure withinthe annular volume.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The foregoing and other aspects and advantages of the present inventionwill be better understood from the following detailed description ofpreferred embodiments of the invention with reference to the drawings,in which:

FIG. 1 is a graph of vapor pressure (Torr) vs. temperature (° C.) ofvarious compositions;

FIG. 2 is a perspective view of the processing system of the presentinvention;

FIG. 3 is a perspective view of four representative processing systemsof the present invention mounted on a typical central wafer handlingsystem;

FIG. 4 is an expanded plan drawing of an embodiment of a liquid deliverysystem (LDS) housing of the present invention;

FIG. 5 is an assembly drawing of a section of an exhaust housing wall ofthe liquid delivery system of FIG. 4;

FIG. 6 is a cross-sectional view of a processing chamber of the presentinvention;

FIG. 7 is a cross-sectional view of a lift mechanism and the lower halfof a processing chamber of the present invention;

FIG. 8 is an assembly drawing of the lift mechanism of FIG. 7;

FIG. 9 is a plan view of the lid of the present invention;

FIG. 10 is a schematic of an embodiment of the chamber assembly of thepresent invention;

FIG. 11 is a perspective view of an embodiment of the remote plasmagenerator of the present invention

FIG. 12 is a perspective view of an embodiment of the exhaust system ofthe present invention;

FIG. 13 is a schematic view of a remote plasma generator of the presentinvention;

FIG. 14 is a perspective view of an embodiment of the vapor deliverysystem of the present invention;

FIG. 15 is a schematic drawing of a representative liquid flowcontroller of the present invention;

FIG. 16 is a schematic drawing of a representative liquid deliverysystem (LDS) and vapor delivery system with one vaporizer;

FIG. 17 is a schematic drawing of a representative LDS and vapordelivery system with two vaporizers;

FIG. 18 is an alternative embodiment of the liquid and vapor deliverysystems of FIG. 2;

FIG. 19 is a schematic drawing of a second representative LDS and vapordelivery system with two vaporizers;

FIG. 20 is an alternative embodiment of the liquid and vapor deliverysystems of FIG. 19;

FIG. 21 is a schematic of an embodiment of the present invention withtwo vaporizers mounted on the chamber lid;

FIG. 22 is a perspective view of an embodiment of the present inventionwith two vaporizers mounted on the chamber lid;

FIG. 23 is a cross-sectional view of an embodiment of the flexibledouble containment line of the present invention;

FIG. 24 is a perspective view of an embodiment of the flexible doublecontainment lines connected to and LDS housing;

FIG. 25 is a perspective view of an embodiment of the present inventionwith two vaporizers mounted on the chamber lid with the chamberlid/vaporizer assembly in the open position;

FIG. 26 is a second perspective view of an embodiment of the presentinvention with two vaporizers mounted on the chamber lid;

FIG. 27 is a third perspective view of an embodiment of the presentinvention with two vaporizers mounted on the chamber lid; and

FIG. 28 is a flow chart illustrating automation of the processing systemaccording to an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The foregoing and other aspects and advantages will be better understoodfrom the following detailed description of the preferred embodiments ofthe invention with reference to the drawings. Like reference numeralsrefer to corresponding parts throughout the drawings.

The present invention is directed to a novel liquid delivery system(LDS), chemical vapor deposition (CVD) chamber, exhaust system, andremote plasma generator that together comprise a unique systemespecially useful for depositing thin metal-oxide films, such as hafniumsilicate, as well as other films requiring vaporization of lowvolatility precursor liquids. This system also provides for an in-situcleaning process that removes the metal-oxide films that are depositedon the interior surfaces of a deposition chamber as a by-product of thedeposition process. The system also has application in making ultralarge scale integration (ULSI) DRAM and other advanced electronicdevices that require the deposition of high dielectric constantmaterials. In general, devices that can be made with the system of thepresent invention are those devices that are characterized by having oneor more layers of insulating, dielectric, or electrode material on asuitable substrate such as silicon. In addition to the previouslymentioned High k materials, the system of the present invention can beused to deposit silicates, aluminates, N-doped silicates, plus othermetal gate electrode materials. One skilled in the art will appreciatethe ability to use alternatives to the disclosed configurations andprocess details of the present invention without departing from thescope of the present invention. In some instances, well knownsemiconductor processing equipment and methodologies have not beendescribed to avoid obscuring the present invention.

FIG. 2, which is a perspective view of the processing system of thepresent invention, shows the relative positions of the main componentsof the present invention. Processing system 100 contains a processingchamber assembly 200, a heated exhaust system 300, a remote plasmagenerator 400, a vapor delivery system 500, and an on-board softwarecontrol system 1000 (FIG. 21). Also shown in FIG. 2 is a centralsubstrate transfer chamber 110 representative of a cluster toolembodiment of the processing system of the present invention. Processingchamber assembly 200 comprises a lid 205 and a chamber body 210 and isattached to central transfer chamber 110. Vapors supplied via vapordelivery system 500 are provided into a processing region (not shown)within chamber assembly 200 via a heated feed-through assembly 220 thatincludes temperature controlled conduits formed within an inlet andmixing manifold 272 and a central mixing block 262. Cartridge heaters264 are integrally formed into each block and, in conjunction withindividual thermocouples and controllers, maintain temperatureset-points within the conduits. During operation, these temperatureset-points may be different for different conduits, blocks, and otherchamber assembly components. For clarity, individual thermocouples andcontrollers have been omitted. Not visible in FIG. 2 but an aspect ofthe present invention is an embedded lid heater 235 (FIG. 6) integratedinto chamber lid 205 beneath a heater clamping plate 234.

Processing by-products are exhausted from chamber assembly 200 viaheated exhaust system 300 that is coupled to chamber assembly 200. Alsoshown are an isolation valve 310, a throttle valve 315, a chamberby-pass inlet 320, a cold trap 325, a cold trap isolation valve 330, anda wafer fabrication plant exhaust treatment system outlet 340 (or“foreline”). In order to provide a clearer representation of theinterrelationship between and relative placement of each of thecomponents of heated exhaust system 300, the jacket type heaters,thermocouples and controllers used to maintain set-point temperatures inexhaust port 305, isolation valve 310, throttle valve 315, chamberby-pass inlet 320, and a by-pass line 322 have been omitted.

Activated species for cleaning are generated by remote plasma generator400 and provided to a processing region within chamber assembly 200 viaconduits within heated plasma manifold 270, and central mixing block262. Other components of remote plasma generator 400 such as magnetron402, auto tuner controller 410, and auto tuner 408 are visible in FIG.2.

The main components of vapor delivery system 500 include a liquid flowmeter 510 and a vaporizer 520. Three-way inlet valve 588 introduceseither a precursor from precursor supply lines 508 or a solvent fromsolvent delivery line 591 into vapor delivery system 500. Precursor fromsupply line 508 enters liquid flow meter 510, which regulates theprecursor liquid that flows to vaporizer 520 through vaporizer supplyline 513. Heat exchanger 530 and gas heater 582 preheat carrier (or“ballast”) gases and process gases respectively. Carrier gases fromcarrier gas source 531 enter heat exchanger 530 and are heated, beforethey travel via a carrier gas supply line 532 to vaporizer 520, tofacilitate more complete vaporization within vaporizer 520 as well ascarry vaporized liquids to chamber assembly 200. After vaporizingprecursor liquid in vaporizer 520, chamber by-pass valve 545 allows thevapor to be ported either to the processing region in chamber assembly200 via chamber outlet 550 and heated feed-through line 560, or toexhaust system 300 via an outlet 555 and heated by-pass line 322.Process gases from process gas source 579 enter gas heater 582 and areheated before they travel via a process gas supply line 586 to chamberassembly 200.

The jacket style heater, thermocouple, and controller that maintain thetemperature of chamber by-pass valve 545 and heated feed-through line560 and the jacket style heater, thermocouple, and controller thatmaintain the temperature of by-pass line 322 have been omitted so as notto obscure the components of vapor delivery system 500 and theirrelationship to chamber assembly 200 and heated exhaust system 300.

The sizes and dimensions of the various components and the placement ofthese components in relation to each other are determined by the size ofthe substrate used in the processes of the present invention. Apreferred embodiment of the invention will be described herein withreference to a processing system 100 adapted to process a circularsubstrate, such as a silicon wafer, having a 200 mm diameter. Althoughdescribed in reference to a single substrate, one of ordinary skill inthe art of semiconductor processing will appreciate that the methods andvarious embodiments of the present invention are adaptable to theprocessing of multiple substrates within a single chamber assembly 200.

Turning now to FIG. 3, which is a perspective view of fourrepresentative processing systems of the present invention mounted on atypical central wafer handling system, a plurality of processing systems100 are arranged in a cluster tool arrangement around central substratetransfer chamber 110 and supported by a mainframe 105. The Centura7mainframe system, manufactured by Applied Materials, Inc. of SantaClara, Calif., is representative of one such cluster tool arrangement.This arrangement allows multiple chambers, shown here comprising fourprocessing systems 100 of the present invention, to connect to a commonvacuum transfer chamber 110.

One advantage of such an arrangement is that the central substratetransfer chamber 110 also has attached to it a loadlock or loadlocksthat hold a plurality of substrates for processing in chambers attachedto the central substrate transfer chamber. Although FIG. 3 illustratesfour identical processing systems 100, another advantage of the clustertool arrangement is the ability to place a variety of chamber types ontoa single central substrate transfer chamber 110. In such an arrangement,a substrate may move between chambers arranged around central substratetransfer chamber 110 without exposure to an air or oxygen ambient. Thus,it is a feature of the processing system 100 of the present inventionthat, with a variety of predetermined chamber types, a substrate couldbe loaded into the loadlock attached to central substrate transferchamber 110, sequenced through the various chambers and, as a result ofthe sequencing, form predetermined and desired films on a substrateprocessed in this manner.

It is contemplated that processing system 100, in conjunction with otherchamber types, is capable of forming complete portions of an IC.Specifically contemplated are the selections of chamber types,sequencing, and liquid delivery configurations that result in theformation of a stack capacitor having polysilicon bottom and topelectrodes separated by silicon nitride and titanium nitride barrierlayers that are separated by a tantalum oxide dielectric layer. Alsospecifically contemplated are the selections of chamber types,sequencing, and liquid delivery configurations that result in theformation of a High k transistor gate stack having an interfacial layeron the bottom interface, followed by a High k dielectric layer, followedby a post treatment, then followed by a gate electrode material. Otherlayers and structures are also contemplated and are intended to beincluded within the capabilities of the methods and apparatus describedherein. It is also specifically contemplated that a single processingsystem 100 would alone have the processing capability of formingcomplete portions of an IC.

Each system 100 is shown with a cover 203 in place. Cover 203 enclosesheated chamber lid 205 and temperature controlled central mixing block262, inlet and mixing manifold 272, and heated plasma manifold 270 (FIG.2). In one embodiment of the present invention, while chamber lid 205 isheated to operate at temperatures from 30° C. to 130° C., cover 203 ismaintained at a relatively safe temperature to prevent burn injuriesfrom contact with the heated components of lid 205.

Remote plasma generators 400 are also shown in an alternative embodimentin which each generator is supported from the top of mainframe 105instead of from below as shown in FIG. 2. So as not to obstruct the viewof this alternative embodiment of remote plasma generator 400, heatedexhaust system 300 is not shown. Such a support arrangement of remoteplasma generator 400 provides easier accessibility and maintenance ofother components of processing system 100 as well as contributing to thereduction of the overall footprint of processing system 100. Theembodiment of the plurality of processing systems 100 of FIG. 3 furtherillustrate the compact design features of the present invention. Anadditional aspect of compact design in this embodiment is that bulkstorage containers and solvent containers are located in an on-board LDShousing 108 on mainframe 105. This reduces the liquid line lengthbetween containers and vaporizers allowing more precise control andrepeatability of liquid delivery.

LDS housing 108 has an exhaust system that allows the user to tune theexhaust to desired flow rates at points within LDS housing 108. Nowreferring to FIG. 4, which is a drawing of an embodiment of a liquiddelivery system (LDS) housing of the present invention (viewed facinghousing doors 116), LDS housing 108 has on its left-hand side an exhaustport 107 that is attached to an exhaust line, typically house exhaust.Exhaust port 107 leads from an enclosed volume 104 created by an exhaustcover 106 and an exhaust housing wall 109. Exhaust cover 106 is showntransparently to reveal that exhaust housing wall 109 is fitted with anumber of slotted plates 111 each covering a section of exhaust housingwall 109. LDS housing 108 has on its right-hand side a second exhausthousing wall 117 with another set of slotted plates 111.

Now referring to FIG. 5, which is an assembly drawing of a section of anexhaust housing wall of the liquid delivery system of FIG. 4, bothexhaust housing walls 109, 117 have horizontal slots 112 and verticalslots 113 (shown as an enlarged section of housing walls 109, 117).Slotted plates 111 have horizontal slots 114 and bolt holes 115 (forclarity, only representative elements have been labeled in this Figure).Horizontal slots 114 on slotted plates 111 and horizontal slots 112 onhousing walls 109, 117 are the same dimensions and are spaced so thatall horizontal slots 114 may align with corresponding horizontal slots112 when a slotted plate 111 is bolted to exhaust housing wall 109 orexhaust housing wall 117. Bolts 118 pass through bolt holes 115 andvertical slots 113 to attach slotted plate 111 to exhaust housing walls109, 117. Vertical slots 113 allow each slotted plate 111 to be boltedbetween a raised position (at bolt position 119) or a lowered position(at bolt position 120) relative to exhaust housing wall 109 or 117. Whenbolted using bolt positions 119 (as shown), horizontal slots 114 arefully aligned with horizontal slots 112. When bolted using boltpositions 120, horizontal slots 114 do not align with horizontal slots112 at all. Fully aligning a horizontal slot 114 with a horizontal slot112 opens a passageway 121 through the combination of slotted plate 111and exhaust housing wall 109 or 117. Bolting plate 111 at a positionbetween bolt positions 119 and 120 creates a partial alignment ofhorizontal slots 114 and 112 and a partial opening of passageway 121.

“Tuning” LDS housing 108 means bolting slotted plates 111 in a positionthat opens passageways 121 a desired amount so that air may flow acrossarbitrary positions within LDS housing 108 at a desired velocity, once avacuum is applied to enclosed volume 104. These arbitrary positionsgenerally correspond to the locations of valves and other plumbingwithin LDS housing 108 that can leak noxious materials. Tuning LDShousing results in air flowing past these valves and plumbing at avelocity that would draw escaping noxious fumes into the house exhaust.For each slotted plate 111, maximum air may flow when horizontal slots114 are aligned with horizontal slots 112 creating passageways 121.Conversely, minimum exhaust may flow when horizontal slots 114 are notaligned with horizontal slots 112 at all and passageways 121 are closed.Partially aligning slots 114 and 112 partially opens passageways 121 andcontrols the flow through passageways 121.

During tuning, LDS housing 108 is fitted with air velocity sensors (notshown) at the desired locations within LDS housing 108. Exhaust port 107is connected to house exhaust, which creates a vacuum within enclosedvolume 104. Opening passageways 121 in exhaust housing walls 109 and 117causes air to flow through the main section of LDS housing 108 and intothe exhaust. The air flow at each of the desired locations is monitoredand adjusted by adjusting the air flow through the appropriate slottedplate 111, or multiple slotted plates 111, which could include plates oneither or both of exhaust housing walls 109, 117. Although LDS housing108 is shown with slotted plates 111 on opposing walls 109, 117, itshould be understood that the invention could be practiced with theslotted plates on different walls and in differently-shaped housings.

Referring briefly to FIG. 24, one embodiment of the invention employs anLDS housing 108A that does not have the tunable exhaust feature of LDShousing 108 (FIG. 3). In this particular embodiment of the invention,LDS housing 108A is attached to mainframe 105 (FIG. 3) in the samemanner as LDS housing 108 (FIG. 3). LDS housing 108A is dimensioned tocontain four bulk storage containers and one bulk solvent container.Precursor supply lines and solvent supply lines connect the bulk storagecontainers and bulk solvent container to vaporizer assemblies on any ofthe processing systems 100 (FIG. 3) attached to mainframe 105. Forclarity, FIG. 24 shows an example with precursor supply lines 508, 508′and solvent supply line 591 connecting the containers (not shown) withinLDS 108A to processing system 100. Typically, LDS 108A is within tenfeet of the attached processing system 100.

LDS housing 108 also has a magnetic proximity switch (not shown) thatmonitors whether housing doors 116 are closed, as part of an interlocksystem. When housing doors 116 are not closed, the interlock systemde-energizes the gas and precursor supply valves. Also, as part of theinterlock system, a sensor (not shown) monitors airflow through exhaustport 107 and the system de-energizes the gas and precursor controlvalves in the LDS housing 108 and the vaporizers should the flow be toolow. These interlocks are listed in Table I, below.

FIG. 6 is a cross-sectional view of chamber assembly 200 of processingsystem 100 of FIG. 2. Heated chamber lid 205 is hinged to chamber body210. Together with O-ring 245 these form a temperature and pressurecontrolled environment or processing region 202 for performingdeposition processes and other operations. Chamber body 210 and lid 205are preferably made of a rigid material such as aluminum, various nickelalloys, or other materials having good thermal conductivity. O-ring 245is formed from a chemical resistant elastomer, perfluoroelastomer, orrubber, such as Chemraz®, Kalrez®, or Viton®, respectively, or othersuitable sealing material specifically designed for use in fluid seals.

When lid 205 is closed as shown in FIG. 6, a processing region 202 isformed that is bounded by a showerhead 240, a pumping plate 208, apedestal heater 250, and chamber lid 205. Pedestal heater 250 (shown inthe raised position for processing) is supported by heater shaft 256,which extends through the bottom of chamber body 210. Heater shaft 256is welded to pedestal heater 250 and they move as one. Imbedded withinpedestal heater 250 is a resistive heater that receives power via aresistive heating element electrical connector 257. A thermocouple inthermal contact with pedestal heater 250 senses the temperature ofpedestal heater 250 and is part of a closed loop control circuit thatallows precise temperature control of pedestal heater 250. A substrate201 is supported by the upper surface of pedestal heater 250 and isheated by the resistive heaters within pedestal heater 250 to processingtemperatures of, for example, between about 400° C. and 500° C. fortantalum films formed using the methods and apparatus of the presentinvention. In one embodiment pedestal heater 250 is made of a ceramicmaterial and is capable of attaining temperatures of from 200° C. to600° C. Substrate 201 can be a substrate used in the manufacture ofsemiconductor products such as silicon substrates and gallium arsenidesubstrates and can be other substrates used for other purposes such assubstrates used in the production of flat panel displays. Pedestalheater 250 and substrate 201 are parallel to showerhead 240.

In an embodiment of the present invention, two sets of resistive heatersare imbedded within pedestal heater 250 in a manner that dividespedestal heater 250 into two heated areas. These heated areas areannular, allowing control of an outside area 297 and an inside area 294of pedestal heater 250. Thermocouples are arranged within inside area294 and outside area 297 to sense the temperatures of these areas andare part of two closed loop control circuits that allow for more preciseoverall temperature control of pedestal heater 250. In an embodiment ofthe invention, inner area 294 is heated to a percentage of outside area297 with a single thermocouple, set in inner area 294, used to controlthe temperature. One of ordinary skill will appreciate that the presentinvention encompasses alternative embodiments in which multiplecontinuous or discontinuous embedded heaters are arranged withinpedestal heater 250 to provide additional heat or greater temperaturecontrol.

Processing chamber assembly 200 is coupled to central transfer chamber110 via an opening 214. A slit valve 215 seals processing region 202 andan enclosed volume 206 from central transfer chamber 110. Pedestalheater 250 may also move vertically below opening 214 so that, when slitvalve 215 is open, a substrate may be moved between the processingregion 202 and central substrate transfer chamber 110.

FIG. 7, which is a cross-sectional view of a lift mechanism and thelower half of a processing chamber of the present invention, and FIG. 8,which is an assembly drawing of the lift mechanism of FIG. 7, describelift assembly 900. Lift assembly 900 moves pedestal heater 250, andtherefore substrate 201, into a specific position within chamberassembly 200 in relation to showerhead 240. Lift assembly also createsan annular space 918 that allows an inert purge gas to be passed fromlift assembly 900 into enclosed volume 206 to pressurize enclosed volume206 and prevent vapor from passing from processing region 202 intoenclosed volume 206.

Briefly referring to FIG. 6, lift assembly 900 includes four lift pins902, which move in evenly spaced holes 281 in pedestal heater 250 aboutheater shaft 256 (two lift pins are not shown for clarity). Lift pins902 interact with a lift plate 904 that attaches to an upper carrier 910(FIG. 7) by way of a lift tube 905. Lift plate 904 is made of aluminumwith four ceramic buttons (not shown) for contacting ceramic lift pins902. When in contact with lift plate 904, lift pins 902 slide verticallywithin holes 281 due to relative movement between pedestal heater 250and lift plate 904. At some point when lowering lift plate 904 thisrelative movement causes lift pins 902 to retract below the surface ofpedestal heater 250 and causes lift plate 904 to lose contact with liftpins 902. Pedestal heater 250 then mechanically retains lift pins 902 bymeans known to one of ordinary skill in the art.

Returning to FIG. 7, lift plate 904, lift tube 905, and heater shaft 256move axially within a bellows assembly. The bellows assembly includes anupper bellows 922A and a lower bellows 922B. Heater shaft 256 issupported by a lower carrier 912. A motor 906 (FIG. 8) moves lowercarrier 912 through a lead screw drive shaft 908 (FIG. 8) and aprecision ground nut (not shown), which could also be a ball nut. Lowerbellows 922B seals against lower carrier 912 and upper carrier 910.Upper bellows seals against upper carrier 910 and chamber mounting plate916. This, in combination with heater shaft 256 creates an annular space918. Annular space 918 provides a passage that conducts a purge gas froma gas inlet 920 into enclosed volume 206. Lift tube 905 is withinannular space 918 and is perforated to allow the purge gas to flowbetween lift tube 905 and upper bellows 922A.

Now referring briefly to FIG. 8, heater shaft 256 is sealed by a heaterconnector 924 that is provided with gas fittings 927. A purge gas isintroduced into the interior of heater shaft 256 through one of gasfittings 927 and exits through the other gas fitting 927. Nitrogen iscommonly used as the purge gas, but other purge gasses are known in theart. Upper and lower carriers 910, 912, lead screw drive shaft 908, andmotor 906 are supported by a lift housing 926. Lift housing 926 isattached to chamber mounting plate 916 through a heater lift levelingplate 928. Heater lift leveling plate 928 has a pivoting connection 930to chamber mounting plate 916 and two adjustable connections 932.Adjustable connections 932 level pedestal heater 250 to shower head 240.

Returning to FIG. 7, during processing, lift pins 902 are retractedbelow or even with the surface of pedestal heater 250. To transfersubstrate 201 out of the process chamber, lower carrier 912 lowersheater shaft 256, which in turn lowers pedestal heater 250 from theprocess position in relative proximity to showerhead 240 to the transferposition where the surface of pedestal heater 250 is below opening 214.As pedestal heater 250 lowers, lift pins 902 contact with lift plate904. With continued lowering, lift pins 902 begin to protrude above thesurface of pedestal heater 250. As they protrude, pins 902 liftsubstrate 201 off pedestal heater 250 a certain distance after whichpedestal heater 250 and lift plate 904 move in unison until pedestalheater 250 is properly aligned with opening 214.

To transfer a substrate into the process chamber, the reverse occurs andlift pins 902 rise with pedestal heater 250 to lift substrate 201 off arobot blade (not shown) that has entered via opening 214. The liftmechanism pauses and the blade then retracts. Pedestal heater 250 thenraises substrate 201 to the programmed process position. During thisraise, pedestal heater 250 and lift plate 904 move in tandem a certaindistance, then lift plate 904 ceases moving while pedestal heater 250continues upward. The relative motion between lift plate 904 andpedestal heater 250 causes lift pins 902 to retract within pedestalheater 250 until lift pins 902 no longer contact lift plate 904.Pedestal heater 250 continues moving until properly positioned.

The relative movement between lift plate 904 and pedestal heater 250 isdetermined by upper and lower carriers 910, 912. As discussed, uppercarrier 910 supports lift plate 904 and lower carrier 912 supportspedestal heater 250 through heater shaft 256. Upper carrier 910 isbiased by springs (not shown) within lift housing 926 to remain againsta hard stop (not shown) until engaged by lower carrier 912 as the lowercarrier descends. Upper carrier 910 and lower carrier 912 then travel inunison until pedestal heater 250 reaches the release position.

During the upward motion, upper carrier 910 is first pulled up by springforce and restrained by the upward motion of lower carrier 912. Uppercarrier 910 stops when it contacts a hard stop (not shown). Lowercarrier 912 continues to travel upward along with pedestal heater 250.This causes a relative motion between lift pins 902 and pedestal heater250 with the lift pins receding within the support until they losecontact with lift plate 904. At the point lift pins 902 lose contactwith lift plate 904, they are recessed within pedestal heater 250. Theposition of pedestal heater 250 is adjusted to space substrate 201within a range of approximately 0.300″ to 1.000″ from showerhead 240.

In one embodiment of the invention, a chamber liner 298 is situatedwithin chamber body 210 and dimensioned to provide a gap 299 betweenchamber liner 298 and chamber body 210. Gap 299 thermally isolateschamber liner 298 from chamber body 210. Chamber liner 298 remains at ahigher temperature than chamber body 210 during processing becausechamber body 210 is in contact with the cooler external ambientatmosphere. Consequently, less condensate forms on chamber liner 298than on chamber body 210. Less condensate also forms on chamber body 210since much of it is shielded from the majority of vapor withinprocessing region 202 by chamber liner 298. Additionally, the small sizeof gap 299 and lack of forced flow from processing region 202 into gap299 reduces the amount of material that diffuses through gap 299 duringprocessing and thereby reduces the amount of condensate that may form onchamber body 210. An additional advantage of this arrangement is thatchamber liner 298 may be removed for cleaning or replacement and chamberbody 210 need not be cleaned as much, resulting in less wear andincreasing the useful life of chamber body 210. In one embodiment of theinvention, gap 299 is approximately 0.100″ wide, although chamber liner298 does occasionally come into contact with chamber body 210 to fixchamber liner 298 into position with chamber body 210.

Returning to FIG. 6, when slit valve 215 is closed and pedestal heater250 is in the raised position for processing, processing region 202 isseparated by pedestal heater 250 from enclosed volume 206. Duringprocessing, gap 207 allows material to pass into enclosed volume 206.This loss is undesirable since it reduces the efficiency of thedeposition process and leads to this material condensing on chamber body210 and chamber liner 298.

To prevent this, enclosed volume 206 is kept at a pressure greater thanprocessing region 202 by introducing an inert gas such as nitrogen intoenclosed volume 206 via gas inlet 920 (FIG. 7). The inert gas flowsthrough annular space 918 (FIG. 7), enclosed volume 206, gap 207,pumping passage 223, to pumping channel 260, through chamber exhaustport 305, and is collected by the heated exhaust system 300. In oneembodiment of the invention the inert gas flows from pumping channel 260directly to isolation valve 310. Pressure transducers (not shown)monitor the pressures in enclosed volume 206 and processing region 202.Pedestal heater 250 is sometimes called a “lift” and this feature ofhaving a greater pressure below the lift is sometimes called a “liftpurge.” The pressure differential from enclosed volume 206 to processingregion 202 reduces material flow from processing region 202 intoenclosed volume 206, reduces maintenance, and improves depositionefficiency. The pressure monitors are interlocked to de-energize the gascontrol valves, heaters, and chamber as listed in Table I, below.

In an embodiment of the invention, a heating channel 211 is providedwithin chamber body 210. A heated fluid, such as water or glycol, ispassed through heating channel 211 to raise the temperature of chamberbody 210 This results in less condensation on chamber body 210 with theadvantages discussed above. In one embodiment, chamber body 210 isheated to operate at temperatures of from 30° C. to 105° C. using waterand a Steelhead 37, manufactured by Neslabs. The water circulated withinheating channel 211 is commonly 90° C. Also, mixing block 262, manifold272, and heated feed-through line 560 are heated to operate attemperatures of from 30° C. to 230° C., and pedestal heater 250 isheated to temperatures of between 200-600° C. In this embodiment thereare sixteen independently controlled temperature zones with safetyovertemperature interlocks downstream of the vaporizers.

Pumping passage 223 and pumping channel 260 are formed within chamberbody 210 for removing by-products of processing operations conductedwithin processing region 202. Pumping channel 260 provides fluid and gascommunication between components of heated exhaust system 300 andprocessing region 202.

Turning now to the gas delivery features of chamber assembly 200, theprocess gas/precursor mixture from vapor delivery system 500 andactivated species from remote plasma generator 400 are delivered viatemperature controlled conduits 273 and 271, respectively, to a centralconduit 231 and a central lid bore-through 230 formed in lid 205. Fromthere, gases and activated species flow through blocker plate 237 andshowerhead 240 into processing region 202.

Temperature controlled conduits 271 and 273 are formed integral toheated feed-through assembly 220 comprising central mixing block 262 andinlet and mixing manifold 272. Although the embodiment represented inchamber assembly 200 of FIG. 6 indicates a heated feed-through assembly220 comprising block 262 and manifold 272, one of ordinary skill willappreciate that the block and manifold can be combined into a singleblock without departing from the spirit of the present invention. Aplurality of cartridge heaters 264 are disposed internally to block 262and manifold 272 and proximally to the conduits 231, 273, 278, 265, and276. Cartridge heaters 264 maintain a set-point in each conduitutilizing separate controllers and thermocouples for the heater of aparticular conduit. For clarity, the separate thermocouples andcontrollers have been omitted.

Lid 205 is also provided with an annular channel 244 that circulatescooling water within that portion of lid 205 in proximity to O-ring 245.Channel 244 is connected to heating channel 211 so that the same fluidcirculates through each. Channel 244 allows the majority of lid 205 tomaintain the temperatures preferred for advantageous heating ofshowerhead 240 while protecting O-ring 245 from higher temperatures thatdegrade the sealing qualities of O-ring 245. This protection is desiredbecause, when degraded, O-ring 245 is more susceptible to attack by thereactive species generated and supplied to processing region 202 byremote plasma generator 400. A flow meter (not shown) monitors the flowthrough channel 244 and is interlocked to de-energize the water heaterand other heater controllers should the flow be too low, as listed inTable I.

Another feature of processing chamber assembly 200 of the presentinvention also shown in FIG. 6 is an annular resistive heater 235embedded within chamber lid 205. This feature of chamber assembly 200provides elevated temperatures in lid 205 in proximity to both centrallid bore-through 230, showerhead 240, and the area between the lowersurface of the lid 205 and showerhead upper surface 263. Formed withinthe top surface of lid 205 is an annular groove shaped according to thesize and shape of heater 235 in order to increase surface contact andheat transfer between heater 235 and chamber lid 205. A clamping plate234 is secured in this groove by fasteners 243 (see FIG. 9) to helpincrease the surface area contact between embedded heater 235 and lid205, thereby improving the efficiency of heat transfer between heater235 and lid 205.

Without heater 235, channel 244 could continuously remove heat fromchamber lid 205. This would lower the temperature of portions of lid205, particularly those in contact with precursor vapor, such as thearea surrounding central lid bore-through 230 and the showerhead uppersurface 263. While cooler lid temperatures improve conditions for O-ring245, cooler lid temperatures could result in undesired condensation ofprecursor vapor. Thus, heater 235 is positioned to heat those portionsof lid 205 in contact with the vaporized precursor flow. As shown inFIG. 6, for example, heater 235 is located between channel 244 andcentral lid bore-through 230 while also positioned to provide heating tothe lid surface adjacent to blocker plate 237.

Referring now to FIG. 9, which is a top view of the lid of the presentinvention, the relationship of heater 235 to other components mounted onlid 205 can be better appreciated. Embedded heater 235 is indicated inphantom and is located beneath clamping plate 234 and electricalconnections 236. Lid 205 also has an embedded thermocouple 204 formonitoring the temperature within lid 205 in proximity to heater 235.Thermocouple 204 is part of a feedback control circuit that monitors andcontrols the power supplied to heater 235 to obtain a set-pointtemperature within lid 205. Precise temperature control is desired inlid 205, as in all components in contact with vaporized precursor gases,to provide conditions that neither condense nor decompose low vaporpressure precursors.

For a representative 200 mm embodiment of chamber assembly 200 shown inFIG. 6, heater 235 could have a 900 W output rating and is commerciallyavailable from a variety of commercial sources such as Watlow, Inc. ofRichmond, Ill. Temperature set-points between about 80° C. and 180° C.are readily obtained in lid 205 utilizing a heater rated at about 650Watts. It will be appreciated that various heater ratings, set-points,and configurations could be utilized to obtain a wide range oftemperature set-points depending upon the decomposition and condensationtemperatures and other characteristics of the precursor material used.Although heater 235 is represented by a single, continuous, circularelement, one of ordinary skill will appreciate that alternativeembodiments wherein a plurality of continuous or discontinuous embeddedheaters 235 are arranged within lid 205 to provide additional heat orgreater temperature control are within the scope of the presentinvention.

Referring again to FIG. 6, heated lid 205 provides support forshowerhead 240 and blocker plate 237. As such, showerhead 240 isattached to lid 205 via a plurality of evenly spaced fasteners 242 andblocker plate 237 is attached to lid 205 by a plurality of evenly spacedfasteners 217. Fasteners 217 and 242 are formed from a rigid materialsuch as aluminum, varieties of nickel alloys, and other materials havinggood thermal conductivity. Fasteners 242 and 217 have beenadvantageously placed to provide clamping force to increase contactbetween heated lid 205 and showerhead 240 in the case of fasteners 242and heated lid 205 and blocker plate 237 in the case of fasteners 217.Increased contact area produces greater heat transfer between heated lid205, blocker plate 237, and showerhead 240. Increased contact area alsoprovides a better seal against gas leaks.

Referring now to FIG. 10, which is a schematic of an embodiment of thechamber assembly of the present invention, specific aspects of thetemperature controlled conduits of chamber assembly 200 of the presentinvention can be more fully appreciated. In particularly, one feature ofthe vapor delivery system of the present invention is represented by thecontinuous, independently temperature controlled conduits that couplethe outlet of vaporizer 520 to processing region 202. Given the lowvapor pressure of the tantalum and hafnium precursors, another featureof the vapor delivery system is the shortened vapor flow path fromvaporizer 520 to processing region 202. Shortening the precursor vaporflow path reduces pumping losses, friction losses, and other fluiddynamic inefficiencies associated with the length of the pumping conduitas well as the inherent difficulties of pumping low vapor pressuregases. The reduction of the above fluid losses is also beneficial to theeffective vaporization and delivery of low vapor pressure precursorsaccording to the present invention because, as a result of minimizingthe precursor flow path, the vapor delivery system is able to attainmore stable and repeatable vapor flow rates for low vapor pressureprecursors. In FIG. 10, for clarity, the schematic contains less detailregarding certain parts of the interior of the chamber assembly, morespecifically from central lid bore-through to the pedestal heater 250.

Heated feed-through assembly 220, which includes inlet and mixingmanifold 272 and central mixing block 262, is formed from rigidmaterials such as aluminum, varieties of nickel alloys, or othermaterials having good thermal conductivity. The various conduits formedwithin heated feed-through assembly 220 couple the outlets of heatedchamber feed-through 225 and process gas chamber feed-through 227 andlid bore-throughs 226 and 228 to central lid bore-through 230.

Inlet and mixing manifold 272 attaches to lid 205 forming a sealed,continuous flow path between a precursor lid bore-through 226 andprecursor inlet conduit 265 and between process gas lid bore-through 228and process gas inlet conduit 276.

O-rings 216, 218, formed from a chemical resistant elastomer,perfluoroelastomer, or rubber for use in fluid seals, such as Chemraz®,or Kalrez®, or Viton® are used at lid bore-through outlets 226 and 228,respectively, to provide a seal at the mating surfaces between lid 205and inlet and mixing manifold 272 and to seal at the mating surfacesbetween lid 205 and chamber body 210. Mixing conduit 278 includes thearea where the process gas and precursor vapor begin to merge into ahomogeneous mixture that is eventually delivered into processing region202. The total conduit length from the beginning of mixing conduit 278to processing region 202 is sufficiently long such that the resultingvapor/gas stream is homogeneously mixed upon arrival in central lidbore-through 230. Although the specific lengths needed to achievehomogeneous mixing will vary depending on a variety of factors such asthe diameter of the conduit and gas flow rates and temperatures, arepresentative length from the beginning of mixing conduit 278 tocentral lid bore-through 230 would be about 9 inches for 0.5 inch innerdiameter mixing conduit 278, mixed deposition gas conduit 273, centralconduit 231, and central lid bore-through 230. In an alternativeexample, the length of conduit that could also result in homogeneousmixing of precursor vapor and process gases from mixing conduit 278through mixed deposition gas conduit 273 and central conduit 231, bothhaving inner diameters of 0.5 inches, is about 10 inches.

Inlet and mixing manifold 272 attaches to central mixing block 262 suchthat the outlet of gas conduit 273 is coupled to mixed deposition gasconduit 293 formed within central mixing block 262. The mating surfacesurrounding the outlet of gas conduit 273 and the inlet of mixeddeposition gas conduit 293 is sealed with an O-ring 213 formed of achemical resistant elastomer, perfluoroelastomer, or rubber designed foruse in fluid seals, such as Kalrez®, Chemraz®, or Viton®. Similarly, themating surface surrounding the conduit outlet of central conduit 231 andthe inlet of central lid bore-through 230 is sealed with an O-ring 222.

To more clearly describe the unique temperature controlled conduitsfeature of heated feed-through assembly 220 of the present invention,inlet and mixing manifold 272 and central mixing block 262 are describedand discussed as separate pieces. One of ordinary skill in the art,however, will appreciate that a single workpiece could be utilizedhaving the described dimensions and characteristics of both inlet andmixing manifold 272 and central mixing block 262 without departing fromthe scope of the present invention.

The temperatures of each of the conduits formed internal to heatedfeed-through assembly 220 (265, 276, 278, 273, 293, and 231) arecontrolled by a plurality of independent units, each having cartridgeheaters 264, thermocouples 274, and controllers 277. One unit controlsthe temperature of conduits 265, 276, and 278 within inlet and mixingmanifold 272; another controls the temperature of conduit 273 withininlet and mixing manifold 272; and another controls the temperature ofconduits 231, 293 within central mixing block 262. In each block, aplurality of cartridge (or fire-rod type) heaters 264 are advantageouslyarranged integral to the given block in proximity to the conduit orconduits within a given block. Multiple heaters provide the mostefficient heating of the particular conduit or conduits within a givenblock as the heaters can be located based upon the size, shape,composition, and thermal conductivity of the particular block as well asthe particular geometry of the conduits. For the representative systemillustrated in FIG. 10, cartridge heaters 264 are about 0.25 inches indiameter, cylindrical in shape, have various lengths, output powercapacities, and are available commercially from Watlow Inc. of Richmond,Ill. under the brand name “Firerod.”

The set-point temperature is maintained within a given conduit byinputting a desired temperature set-point into the controller 277 forthe particular conduit. Controller 277 could be a PID type controllersimilar to Model 96 that is also commercially available from Watlow,Inc. Thermocouples 274 are embedded within heated feed-through assembly220 in proximity to each conduit such that the temperature registered byeach thermocouple 274 is approximately the same as the temperaturewithin the controlled gas conduit. The position of thermocouple 274relative to a given gas conduit varies depending upon a number offactors such as the thermal conductivity of the material used tofabricate the given block and the type of thermocouple 274 used. Thesignal from thermocouple 274 is sent to controller 277, which comparesthe temperature from thermocouple 274 to the input temperatureset-point. Based on the result of this comparison, controller 277 willeither increase, decrease, or maintain power supplied to cartridgeheaters 264. One advantage of utilizing a plurality of independentthermocouples 274 is that the specific conditions of a given conduitblock are taken into account depending upon its geometry, heat losses,and location relative to other sources of heat.

For example, inlet and mixing manifold 272 is in direct contact withheated lid 205. Unless the temperatures between manifold 272 and lid 205exactly match, manifold 272 will either gain energy from or lose energyto lid 205. The effect of heat transfer between lid 205 and inlet andmixing manifold 272 on the temperature of conduits 265, 276, and 278within manifold 272 will be reflected in the temperature detected by athermocouple 274 located within manifold 272. As a result, thecontroller 277 associated with manifold 272 can increase or decrease thepower output of cartridge heaters 264 embedded within manifold 272 inproximity to conduits 265, 276, and 278 to compensate for heat transferbetween manifold 272 and lid 205. In the same way, energy transferbetween central mixing block 262 and lid 205 is compensated for by thethermocouple, heater, and controller unit associated with block 262. Anadditional advantage of independently controlling separate areas is thatthese areas can be heated to different temperatures.

Heat losses from conduit 273 are different from heat transfer in otherconduits within manifold 272 and block 262. Gas conduit 273 has a higherpotential for heat loss because that part of mixing manifold 272 is notin direct contact with heated lid 205 and has a larger surface area thatis exposed to the ambient conditions (about 25 degrees Celsius withinthe wafer fabrication facility) when cover 203 is removed. When cover203 is in place, however, as illustrated in FIG. 2, temperaturessurrounding heated feed-through assembly 220 increase to about 70 to 80degrees Celsius. Thus, the heater, thermocouple, and controller unitdedicated to gas conduit 273 are utilized to compensate for the heattransfer characteristics peculiar to that conduit.

More generally, an aspect of the present invention is an apparatus toprovide a predetermined temperature within a conduit by the selection,placement, and use of a controller, heater, and thermocouple controlunit that utilize the apparatus described above. Another feature of themultiple, independent cartridge heater, thermocouple, and controllerunits of the present invention is that a uniform conduit temperaturethroughout heated feed-through assembly 220 can be achieved. Because oftheir independence, each controller is able to efficiently maintainset-points irrespective of conditions in surrounding blocks, whiletaking into account: the specific heat losses and conditions surroundingeach block, the specific outer shapes of each block, and the geometry ofthe conduits formed within each block.

In another aspect of the present invention, the temperature set-point ofeach conduit could be set and maintained to induce a negativetemperature gradient where the set-point temperature of central conduit231 is less than the set-point of conduit 273 and the temperature ofconduit 273 is less than that of conduit 278. Alternatively, a positivetemperature gradient could be induced where the temperature increasesfrom conduit 278 to conduit 273 to central conduit 231.

In a specific embodiment of the apparatus of chamber assembly 200 of thepresent invention, mixing manifold 272 is aluminum with the followingdimensions: about 7 inches long, about 3.2 inches wide, and about 3.2inches high. A representative cartridge heater 264 for this block iscylindrically shaped, 0.375 inches in diameter, and 7.0 inches long witha total power output capacity of 500 Watts. In an embodiment of themethod and apparatus of the present invention, a single cartridge heater264 or a plurality of heaters 264 of a selected total power outputcapacity of about 500 Watts is employed about conduit 273 so that thetemperature within mixed deposition gas conduit 273 remains above thevaporization temperature and below the decomposition temperature of thecarrier gas/precursor vapor/process gas mixture flowing within conduit273.

In a specific embodiment where gas conduit 273 is as described above, athermocouple 274 could be placed between about 0.125 inches to 0.5inches away from mixed deposition gas conduit 273. In an embodiment ofthe present invention where the carrier gas/precursor vapor/process gasmixture within conduit 273 comprises a hafnium precursor, a process gassuch as oxygen, and a carrier gas such as nitrogen, conduit 273temperatures between about 130° C. and 160° C. would prevent bothcondensation and decomposition of the hafnium/oxygen/nitrogen mixture.

A further aspect of the temperature controlled conduits of chamberassembly 200 of the present invention provides temperature controlleddelivery of vaporized precursor from vaporizer 520 to central lidbore-through 230. Vaporized precursor exits vaporizer 520 via vaporizeroutlet 540 and enters vaporizer outlet manifold 542 that is coupled tovapor inlet 544 of chamber by-pass valve 545. When by-pass valve 545 ispositioned to direct flow to processing region 202, precursor vaporexits by-pass valve 545 via chamber outlet 550 flowing then to heatedfeed-through line 560 that is coupled to heated precursor feed-through225. In an embodiment of the invention heated feed-through line 560 andheated precursor feed-through 225 are one part. A jacket typetemperature controller controls the temperature in conduit 290 betweenthe inlet 544 of three-way valve 545 and the inlet to heated precursorfeed-through 225, encompassing line 560 and by-pass valve 545. Thejacket type temperature controller comprises a jacket or wrap styleheater 275, a controller 277, and a thermocouple 274 and is utilized tomaintain a temperature set-point in line 560 and valve 545. Thetemperature in manifold 542 is controlled by a separate jacket typetemperature controller. From a temperature-controlled precursorfeed-through conduit 225, precursor vapor flows through precursor lidbore-through 226 into precursor inlet conduit 265 of inlet and mixingmanifold 272. An airtight seal is maintained between precursorfeed-through conduit 225 and precursor lid bore-through 226, and betweenprocess gas chamber feed-through 227 and process gas bore-through 228using O-rings and a correct fit of chamber lid 205 to chamber body 210.From precursor inlet 265, the precursor vapor flows into mixing conduit278 where it mixes with process and carrier gases supplied via processinlet conduit 276.

The temperature of precursor vapor within precursor feed-through conduit225 is maintained by a temperature controlled chamber feed-through 219,which includes a plurality of cartridge heaters 264, a thermocouple 274,and a controller 277. Another feature of temperature controlled chamberfeed-through 219 is thermal choke or air gap 212. Air gap 212 is annularabout precursor feed-through conduit 225, cartridge heaters 264, andthermocouple 274 and insulates the components of temperature-controlledchamber feed-through 219 from the thermal influences of chamber body210. Thus, by utilizing the plurality of heaters, controllers andthermocouples described above and the features of heated lid 205,chamber assembly 200, and vapor delivery system 500, the inventionprovides a temperature controlled flow path for vaporized low vaporpressure precursors from vaporizer 520 to processing region 202.

Process gas heater 582 provides temperature control for process gas andcarrier gases for use in chamber assembly 200. Process gas heater 582 islocated proximally to chamber body 210 and, more specifically, toprocess gas chamber feed-through 227 such that the gas temperatureexiting gas heater 582 is approximately the same as the gas temperatureentering process gas chamber feed-through 227. From process gas chamberfeed-through 227, temperature controlled process and carrier gases passthrough process gas lid bore-through 228 and enter process gas inlet 276of inlet and mixing manifold 272.

Another aspect of the present invention is the use of process gas heater582 to heat process gas and carrier gases above the temperature of thevaporized precursor gas stream. This virtually eliminates the risk thatthe vaporized precursor will condense when the heated process gas streamand the vaporized precursor gas stream intersect and mix within mixingconduit 278. For example, the temperature set-point of process gasheater 582 could be about 5-10° C. above the temperature set-point ofvaporizer 520. Alternatively, a set-point could be utilized that resultsin process gas temperatures at least as high as the merging precursorvapor stream. In much the same way, to prevent precursor decomposition,the temperature of process gas and carrier gas can be controlled toremain below a set-point where decomposition would occur upon mixingwith the precursor vapor stream.

Another aspect of the independent temperature controlled conduits ofchamber assembly 200 is that temperature changes within a specificconduit associated with the volume expansion can be compensated for bythe independent heater, controller and thermocouple of that particularconduit. For example, heated feed-through line 560 and vaporizer outletmanifold 542 are heated by separate thermocouples, controllers, andjacket style heaters (not shown) so that temperatures within heatedfeed-through line 560 and vaporizer outlet manifold 542 can beindividually maintained above the condensation temperature and below thedecomposition temperature of the vaporized precursor, or between about100° C. and 190° C.

The independently temperature-controlled conduits feature of the presentinvention provides for a more precise temperature control thanpreviously available and this allows for delivery of vaporized liquidunder a variety of thermal conditions that exist as a result of thedifferent environments to which each conduit is exposed. Utilizing theindependent thermocouple, controller, heater units that are part ofprocessing system 200 and vapor delivery system 500, a series oftemperature controlled conduits is provided that can deliver vaporizedlow vapor pressure precursors from the outlet of vaporizer 520 toprocessing region 202. For example, each temperature controlled conduitcould be set to maintain a set-point 2-3° C. hotter than the previousconduit so that a slightly positive thermal gradient is maintainedbetween the vaporizer 520 and outlet of central conduit 231 intoprocessing region 202 or, more generally, an overall change intemperature could be maintained between the vaporizer outlet temperatureand the temperature in central conduit 231, or a change in temperatureof about 20-25° C.

Although the heater type is specified in describing conduit temperaturecontrol (such as with cartridge heater temperature controlled conduit293 and jacket heater temperature controlled conduit 279) thesedescriptions are not intended to be limiting. One of ordinary skill inthe art will appreciate that a variety of heater types, thermocouples,and controllers can be utilized without departing from the scope of thepresent invention.

There is another aspect to the thermally controlled conduits ofprocessing chamber assembly 200 and vapor delivery system 500 of thepresent invention. The conduits used downstream of vaporizer 520 in theprecursor flow path, as shown in FIG. 10 between vaporizer 520 andcentral lid bore-through 230, have progressively larger diameters thatresult in increasing cross-sectional flow areas resulting in an expandedgas flow volume within these conduits. The volume expansion andcorresponding pressure drop within the precursor delivery conduitsfurther help maintain conduit conditions that neither condense nordecompose the vaporized precursor. These conditions are above the vaporcondensation temperature, yet below its decomposition temperature forthe pressure within the vapor supply conduits. For example,representative inner diameters for the chamber illustrated in FIG. 10,are a vaporizer outlet manifold 542 with an inner diameter of 0.18inches, a heated feed-through line 560, chamber feed-through 225, andinlet 265 with inner diameters of 0.40 inches and a mixed deposition gasconduit 278 and central conduit 231 with inner diameters of about 0.5inches. For another example, the cross-sectional area of conduit 273downstream of the intersection of the precursor gas flow and the processgas flow is larger than the sum of the merging gas flows.

The increased volume and correspondingly decreased pressure achieved byadvantageously selecting the diameter of manifolds, conduits, and lines,such as 542, 560, 225, 226, 265, 278, 273, 293, and 231 (all downstreamfrom vaporizer 520) in conjunction with the temperature control providedby the thermocouple, heater, and controller sets described above providea controlled temperature and pressure regime between vaporizer 520 andprocessing region 202 such that very low vapor pressure precursors,dopants, or other processing materials, may be delivered to processingarea 202 without undesired condensation or decomposition.

Referring now to FIG. 11, which is a perspective view of an embodimentof the remote plasma generator of the present invention, another aspectof the processing system 100 of the present invention is a remote plasmagenerator 400, chamber assembly 200, and components of heated exhaustsystem 300. Remote plasma generator 400 creates a plasma outside of orremote to processing region 202 for cleaning, deposition, annealing, orother processes within processing region 202. One advantage of remoteplasma generator 400 is that the generated plasma or activated speciescreated by remote plasma generator 400 may be used for cleaning orprocess applications within the processing region without subjectinginternal chamber components such as pedestal heater 250 or showerhead240 to the plasma attack that usually results when conventional RFenergy is applied within process region 202 to create a plasma. Severalcomponents of remote plasma generator 400 are visible, such as magnetron402, auto tuner controller 410, isolator 404, auto tuner 408, applicatorcavity 416, and applicator heat insulation disc 424.

Magnetron assembly 402 houses a magnetron tube, which produces microwaveenergy. The magnetron tube comprises a hot filament cylindrical cathodesurrounded by an anode with a vane array. This anode/cathode assemblyproduces a strong magnetic field when it is supplied with DC power froma power supply. Electrons in this magnetic field follow a circular pathas they travel between the anode and the cathode. This circular motioninduces voltage resonance, or microwaves, between the anode vanes. Anantenna channels the microwaves from magnetron 402 to isolator 404 andwave guide 406. Isolator 404 absorbs and dissipates reflected power toprevent damage to magnetron 402. Wave guide 406 channels microwaves fromisolator 404 into auto tuner 408. Auto tuner 408 compensates fordifferences between the impedance of magnetron 402 and the impedance ofmicrowave applicator cavity 416 to achieve the minimum degree ofreflected power by adjusting the vertical position of three tuning stubslocated inside auto tuner 408. Auto tuner 408 also supplies a feedbacksignal to the magnetron power supply to continuously adjust the actualforward power to the set-point. Auto tuner controller 410 controls theposition of the tuning stubs within auto tuner 408 to minimize reflectedpower. Auto tuner controller 410 also displays the position of the stubsas well as forward and reflected power readings.

Microwave applicator cavity 416 ionizes a gas or gases supplied via gassupply inlet 412. Gas supplied via gas supply inlet 412 enters a watercooled quartz or sapphire tube within microwave applicator cavity 416,is subjected to microwaves and ionizes. This produces activated speciesthat can be used in cleaning and processing operations within processingregion 202. One such cleaning gas is NF₃ that can be used to supplyactivated fluorine for cleaning processing region 202. Activated speciescan also be used to anneal or otherwise process semiconductor or othermaterials present on a substrate 201 positioned within processing region202. An optical plasma sensor 414 detects the existence of plasma withincavity 416. Activated species generated within cavity 416 are suppliedto activated species chamber feed-through 229 via adapter tube 418.Adapter tube 418 is insulated from the elevated temperature of chamberbody 210 by adapter tube heat insulation disc 424. In an embodiment ofthe invention, adapter tube 418 is eliminated and activated species aresupplied directly to activated species chamber feed through from cavity416.

From activated species chamber feed-through 229, the activated speciespass through lid bore-through 221 and enter heated plasma manifold 270that provides an O-ring sealed, air tight conduit (activated speciesconduit 271) between lid bore-through 221, and central gas feed-through231 within central mixing block 262. In an embodiment of the invention,the remote plasma generator uses RF energy, rather than microwave.

Referring FIG. 12, which is a perspective view of an embodiment of theexhaust system of the present invention, the components and features ofheated exhaust system 300 of processing system 100 can be betterappreciated. The components of heated exhaust system 300 arecollectively referred to as a foreline. The foreline is in communicationwith a vacuum pump (not shown) and wafer fabrication facility exhaustsystems (not shown) to provide for reduced pressure processingoperations within processing region 202. Exhaust from processing andcleaning operations conducted within processing region 202 is exhaustedvia chamber exhaust port 305. In this embodiment of the invention,exhaust port 305 (FIG. 2) is eliminated and the exhaust processingregion 202 is exhausted directly into isolation valve 310. When closed,isolation valve 310 shuts off chamber assembly 200 from down streamvacuum pump systems. During normal operation, isolation valve 310 isopen and throttle valve 315 opens and closes to regulate pressure withinprocessing region 202. By-pass inlet 320 (FIG. 2) receives precursorvapor/carrier gas mixture from chamber by-pass valve outlet 555 (FIG.10) when chamber by-pass valve 545 (FIG. 2) is positioned to flowprecursor vapor/carrier gas mixture to temperature controlled by-passline 322 (FIG. 2). Exhaust system components (chamber exhaust port 305,isolation valve 310, throttle valve 315, by-pass inlet 320, and by-passline 322) are temperature controlled to prevent unreacted precursorcondensation. Cold trap 325 and the remaining downstream exhaust systemcomponents are maintained at or below room temperature. In an embodimentof the invention, the temperatures of the cold trap 325 and theremaining downstream exhaust system components are not maintained at aspecific temperature.

As a result, any unreacted vapor remaining in the exhaust stream fromprocessing region 202, or vapor from chamber by-pass valve 545 willremain gaseous in the temperature controlled or heated portion ofexhaust system 300 and then condense within cold trap 325 thuspreventing damage to the vacuum pumps or accumulation and resulting lineblockages within exhaust system piping. Additionally, collection ofunreacted vapor within cold trap 325 also minimizes the exposure ofmaintenance personnel to potentially hazardous chemicals. Cold trap 325is equipped with an isolation valve 330 for separating cold trap 325from vacuum pumping systems to allow for routine maintenance orcleaning.

To provide a clear illustration of the relationships between the variouscomponents of exhaust system 300 and the other components of processingsystem 100, the independent thermocouple, controller, and heaterutilized as part of the temperature controlled feature of exhaust system300 is not shown in FIG. 12. Turning briefly to FIG. 16, which is aschematic drawing of a representative liquid delivery system (LDS) andvapor delivery system with one vaporizer, the temperature controlledconduits of exhaust system 300 appear more clearly. A jacket styleheater 275, thermocouple (not shown), and controller (not shown) areutilized to measure and maintain a set-point temperature in chamberexhaust port 305, isolation valve 310, throttle valve 315, and chamberbypass inlet 320, thereby combining to create a jacket heater controlledconduit 292 in the exhaust components upstream of cold trap 325. Chamberby-pass line 322 is included in another jacket style heater temperaturecontrolled conduit 291 between chamber by-pass valve 545 and exhaustby-pass inlet 320 using a separate thermocouple, controller, and heater275.

Turning now to FIG. 14, which is a perspective view of an embodiment ofthe vapor delivery system of the present invention, the compact designfeature of vapor delivery system 500 of the present invention can bebetter appreciated. Vapor delivery system 500 provides a method and anapparatus for supplying controlled, repeatable, vaporization of lowvapor pressure precursors for film deposition on a substrate 201 locatedwithin processing region 202. One method provides for the directinjection of vaporized High k precursors. One of ordinary skill willappreciate the specific features detailed below that allow vapordelivery system 500 to vaporize and precisely control the delivery ofliquid precursors including those precursors having vapor pressuressignificantly lower than precursors utilized in prior art vapor deliverysystems or, specifically, precursors having vapor pressures below about10 Torr at 100° C. (FIG. 1).

The various components of vapor delivery system 500 are placed in closeproximity to chamber assembly 200 in order to minimize the length oftemperature controlled vapor passageways between the outlet of vaporizer520 and processing region 202. Even though practice in the semiconductorprocessing arts is to place vapor systems remotely from processingchambers to either ensure serviceability or reduce the amount ofcleanroom space occupied by a processing system, vapor delivery system500 of the present invention utilizes an innovative compact design thatallows all system components—except for the bulk liquid precursor,carrier gas, and process gas supplies—to be located directly adjacent tochamber assembly 200 and in close proximity to precursor and process gaschamber feed-throughs 225 and 227.

A low vapor pressure liquid precursor can be stored in a bulk storagecontainer (ampoule) 503 located remotely or on mainframe support 105 inLDS housing 108 (FIG. 3) in closer proximity to processing chamberassembly 200. Locating bulk storage containers and solvent containers inon-board LDS housing 108 on mainframe 105 reduces the liquid line lengthbetween containers and vaporizers allowing more precise control andrepeatability of liquid delivery. Liquid precursor stored in container503 is maintained under pressure of an inert gas such as Helium at about15 to 60 psig supplied by supply line 507 (FIGS. 16 and 17). The gaspressure within container 503 provides sufficient pressure on the liquidprecursor such that liquid precursor flows to other vapor deliverysystem components, thus removing the need for a pump to deliver theliquid precursor. The outlet of container 503 is provided with ashut-off valve (not shown) to isolate bulk storage container 503 formaintenance or replenishment of the liquid precursor. As a result of thepressure head on container 503, liquid precursor from container 503 isprovided to a precursor supply line 508 and the precursor inlet 509 ofthree-way inlet valve 588. When valve 588 is set to pass through liquidprecursor, three-way inlet valve 588 provides liquid precursor toprecursor/solvent outlet 594 and into precursor/solvent supply line 592to liquid flow meter inlet 505. Liquid flow meter 510 measures precursorflow rate and provides liquid precursor via liquid flow meter outlet 511(FIGS. 15, 16, and 17) to vaporizer supply line 513 and then tovaporizer inlet 515. Vaporizer 520 in conjunction with a heated carriergas (described below) converts the liquid precursor into precursorvapor.

Carrier gas supply line 525 supplies a carrier gas, such as nitrogen orhelium, to carrier gas heat exchanger 530 at a pressure of about 50Torr. Carrier gas heat exchanger 530 preheats the carrier gas to atemperature such that the heated carrier gas stream entering vaporizer520 does not interfere with the efficient vaporization of the precursorliquid undergoing vaporization within vaporizer 520. Carrier gas heatexchanger 530 heats the gas using a resistive heater like the carriergas heat exchanger Model HX-01 commercially available from Lintec.Heated carrier gas is provided to vaporizer 520 via carrier gas supplyline 532 and carrier gas inlet 535. The heated carrier gas should not beoverheated because a carrier gas heated above the decompositiontemperature of the precursor undergoing vaporization could result inprecursor decomposition within vaporizer 520. Thus, carrier gas heatexchanger 530 heats the carrier gas into a temperature range bounded bythe condensation temperature of the precursor at the lower limit and thedecomposition temperature of the precursor at the upper limit.

For a hafnium precursor a representative vaporization temperature isabout 130° C. and a decomposition temperature is about 190° C. A typicalcarrier gas such as nitrogen is provided to a vaporizer 520 that isvaporizing a hafnium precursor at about between 200 and 2000 standardcubic centimeters per minute (sccm) and a temperature of between about110° C. and about 160° C. These conditions result in a vaporizedprecursor flow rate in the range of about 10-50 milligrams per minute.In an embodiment of the invention the vaporization temperature can beset up to 180° C.

Carrier gas temperature should also be such that the temperature of thecarrier gas entering vaporizer 520 is at least as high if not higherthan the vaporization temperature of the precursor being vaporized invaporizer 520. Of particular concern is the prevention of precursorvapor condensation within the small diameter conduits that exist withinvaporizer 520. Carrier gas temperatures below vaporization conditionswithin vaporizer 520 could cool the vaporized precursor enough thatcondensation results and should therefore be avoided.

Referring now to FIG. 15, which is a schematic drawing of arepresentative liquid flow controller of the present invention, liquidflow controller 528 includes a liquid flow meter 510 and a vaporizer520. Liquid precursor enters liquid flow meter 510, which generates ameasured flow rate signal 512. The precursor flows from liquid flowmeter outlet 511 into vaporizer supply line 513 and then into vaporizerinlet 515. Located within vaporizer 520 between vaporizer inlet 515 andmetering valve 524, is a positive shut-off valve 522 that provides thecapability to cut-off liquid flow before the vaporization point withinvaporizer 520. Vaporizer 520 reads signal 512 and adjusts metering valve524 to achieve a target flow. Positive shut off valve 522 is a pneumaticvalve that is controlled by on-board software control module 1000 (FIG.21). Although metering valve 524 can provide a shut-off capability whenin a “closed” or zero set-point condition, positive shut-off valve 522provides added assurance that no liquid will continue to flow throughvaporizer 520 when liquid flow controller 528 is in a “closed” or zeroset-point condition. The location of positive shut-off valve 522relative to metering valve 524 is such that there is a minimal volume ofliquid that could remain in the line between shut-off valve 522 andmetering valve 524.

A typical flow rate signal 512 is measured in milligrams per minute ormg/min. A representative flow rate for a High k precursor is 7 mg/minfor a representative HfO₂ film produced utilizing the method andapparatus of the present invention.

A representative vaporizer 520 suitable for vaporization of low vaporpressure liquids could position positive shut-off valve 522 about oneinch or less from metering valve 524. For example, using a 0.125 inchouter diameter line between shut-off valve 522 and metering valve 524creates a liquid precursor volume of about 0.012 cubic inches. Reducingthe volume between these components minimizes the amount of precursorthat could vaporize after positive shut-off valve 522 is closed.Positive shut-off valve 522 could also be a type of valve known as a“zero dead volume” valve.

Another aspect of liquid flow controller 528 is that the length ofvaporizer supply line 513, which is typically 0.069 inch inner diameterstainless steel piping is minimized to attain controllable low vaporpressure precursor output from vaporizer 520. Minimizing the length ofsupply line 513 allows more effective liquid metering and control byminimizing the distance between the liquid flow meter outlet 511 andvaporizer inlet 515. Spacing between vaporizer inlet 515 and liquid flowmeter outlet 511 of about 3.4 inches or between about 2 inches and 15inches leads to more effective metering and controlled vaporization oflow vapor pressure precursors, for example liquid precursors having avapor pressure below about 10 Torr at 100° C.

In an embodiment of the invention, liquid flow meter 510 contains themetering valve 524 and vaporizer 520 does not. In this embodiment liquidflow meter 510 measures the flow and also adjusts the flow using theself-contained metering valve 524. As a result, there is no flow ratesignal 512 between vaporizer 520 and liquid flow meter 510, vaporizer520 vaporizes the flow, but vaporizer 520 does not perform a meteringfunction.

Minimizing the distance between liquid flow meter 510 and vaporizer 520,however, adds to the number of vapor delivery system components placedin proximity to chamber assembly 200 and increases the density ofequipment mounted on chamber assembly 200. But vapor delivery system500, along with the remote plasma generator 400, and heated exhaustsystem 300, have been designed to minimize interference between thesubsystems of processing system 100 while achieving the compact designdesired in cluster tool wafer processing systems.

Returning to FIG. 14, vaporized precursor flows from vaporizer outlet540, into vaporizer outlet manifold 542, then into vapor inlet 544 oftemperature controlled by-pass valve 545. When valve 545 is set to passvaporized precursor to the chamber, by-pass valve 545 supplies vapor tochamber outlet 550 and then into temperature controlled heatedfeed-through line 560. The thermocouples, controllers, and jacket styleheaters that maintain a temperature set-point within vaporizer outletmanifold 542, chamber by-pass valve 545, and heated feed-through line560 are a feature of the vapor delivery system 500, but are omitted forclarity. The internal piping of chamber by-pass valve 545 allows thevaporized precursor/heated carrier gas mixture to be sent to processingregion 202 via chamber outlet 550.

Additionally or alternatively, while stabilizing vapor flow orconducting cleaning operations within processing region 202, chamberby-pass valve 545 could direct the vaporized precursor/heated carriergas mixture to heated by-pass line 322 (FIG. 2) of heated exhaust system300 (described above) via outlet 555. One advantage of chamber by-passvalve 545 of the present invention is that once liquid flow controller528 attains a desired set-point vapor flow rate the vaporizedprecursor/heated carrier gas mixture can either be directed to thechamber for deposition or to the foreline by-pass inlet 320 fordisposal. Thus, independently from any operations within processingregion 202, liquid flow controller 528 continues to produce a stable,consistent vapor flow rate. And chamber by-pass valve 545 used inconjunction with liquid flow controller 528 provides repeatable, stablevapor flow rates to consecutive substrates 201 within processing region202. Such repeatable, stable vapor flow rates are desired for thedeposition of transition metal dielectric materials such as tantalumoxide for used in ICs in devices such as stacked capacitors and hafniumoxide for use in ICs in devices such as High k transistors.

Vaporizer outlet manifold 542 and heated feed-through line 560 arestandard piping that could be made of stainless steel. Heatedfeed-through line 560 should be as short as possible to minimize thelength of travel of vaporized precursor within the system to betweenabout 4 to 6 inches. Heated feed-through line 560 is in communicationwith chamber outlet 550 and precursor chamber heated feed-through 225.

To prevent condensation of the vaporized precursor within the vaporizedprecursor/heated carrier gas mixture, heated feed-through line 560 andvaporizer outlet manifold 542, like all precursor supply conduitsdownstream of vaporizer 520, have an inner diameter that is greater thanthe inner diameter of the liquid supply line into vaporizer 520. Asdiscussed previously regarding FIG. 15, the vaporizer liquid supply lineis typically made of stainless steel with about a 0.069 inch innerdiameter while the conduits downstream of vaporizer 520 could have alarger diameter, such as an outer diameter of about 0.5 inches, or aninside diameter of about 0.4 inches.

Vapor delivery system 500 also has a temperature controlled process gasfeature. Process gas heater 582, which is similar to carrier gas heatexchanger 530 described above, receives process gas via supply line 580from a process gas supply. Suitable process gases depend on the desiredfilm deposition. Typically, oxygen (O₂) and nitrous oxide (N₂O) aresuitable for oxidation processes and ammonia (NH₃) is suitable fornitride processes. Additionally, nitrogen (N₂) could be added to theprocess gas flow as a carrier gas. The term process gas stream usedbelow refers to all gas flows out of gas heater 582 and is intended toinclude process gas, carrier gases, or other gases described above.

Process gases and carrier gases are preheated by process gas heater 582so that the resulting process gas stream is maintained above thetemperature of the adjacent vaporized precursor gas stream. Maintainingthe process gas stream temperature about 10°-15° C. above thetemperature of the vaporized precursor gas stream assists in theprevention of inadvertent condensation of the precursor vapor when thegas streams intersect and begin to mix within mixing conduit 278.Similarly, gas heater 582 also helps ensure that process gas streamtemperatures are maintained below the decomposition temperature of theprecursor gas stream so that inadvertent decomposition of the precursorvapor stream does not occur when the gas streams mix within mixingconduit 278.

Thus, a temperature controlled gas stream exits process gas heater 582via outlet 584 and enters process gas supply line 586. Returning brieflyto FIG. 10, from process gas supply line 586 the process gas streamflows through process gas chamber feed-through 227 that in turn flowsinto heated process gas inlet conduit 276. Process gas inlet conduit 276flows into and mixes with vaporized precursor flow stream in heatedmixing conduit 278.

Referring again to FIG. 14, another feature of vapor delivery system 500is the ability to provide a solvent flush capability to those conduitsthat come into contact with the vaporized low vapor pressure precursors.Such solvent operations complement the ability of the method andapparatus of the present invention to vaporize low vapor pressureliquids with the ability to clean the apparatus afterwards. A solventsuch as anhydrous isopropyl alcohol, methanol, hexane, ethanol, or othersuitable solvent is supplied from a bulk solvent container 589 intoprecursor/solvent three-way valve 588 via solvent delivery line 591 andinlet 590. From three-way valve 588 the solvent follows the same flowpath as a vaporized precursor through the various components of vapordelivery system 500 and, depending upon the alignment of chamber by-passvalve 545, to chamber assembly 200 or exhaust system 300 via by-passline 322. As the solvent flows through the various conduits that areexposed to liquid precursor, such as the conduits of liquid flowcontroller 528, the solvent mixes with precursor liquid and purges theline of residual precursor. This allows a subsequent exposure of thecomponents to air for maintenance or component change. Because of thelow vapor pressure of typical precursors vaporized using the methods andapparatus of the present invention, without the solvent flush capabilityresidual precursor vapors within conduits would not be sufficientlyevacuated nor achieve reduced pressures in a timely—commerciallyviable—manner simply using only pumping system 355 of exhaust system300. Additionally, the solvent flush feature can be used to removeprecursor vapor from process conduits and components to prevent risk ofexposure to potentially hazardous materials during maintenance as wellas prevent the undesired reaction of precursor vapor with air, watervapor, or other materials.

FIG. 16 is a schematic drawing of a representative LDS and vapordelivery system with one vaporizer and FIG. 17 is a schematic drawing ofa representative LDS and vapor delivery system with two vaporizers.FIGS. 16 and 17 allow a better understanding of an integrated method ofoperating processing system 100 and the use and interoperability ofdopant, second dielectric, or second precursor materials within thevarious embodiments of the present invention. FIG. 16 schematicallyrepresents a system configuration using a single vaporizer and processheat exchanger to provide process gas/precursor vapor mixtures throughtemperature controlled conduits to processing region 202.

FIG. 17 is similar to FIG. 16 with the addition of a second vaporizer521, bulk container 504 and by-pass valve 570. Flow through secondvaporizer 521 is controlled as discussed regarding vaporizer 520, butfor clarity the elements associated with a second liquid flow controllerare not shown. Under the representative configuration of FIG. 17,processing system 100 of the present invention is further enabled to notonly provide, mix, and deposit films from a single precursor, but also,by modifying the liquid source contained in bulk container 504, filmscontaining a second precursor, a dopant, or a metal.

Processing system 100 as embodied in FIG. 17 operates similarly toprevious descriptions of processing system 100 with the addition of anadditional bulk container 504, which could be under a pressure head aswith bulk supply container 503. Bulk container 504 is coupled to andsupplies processing fluids to a second vaporizer 521, which operatessimilarly to the first vaporizer 520 as embodied in FIG. 16 anddescribed above. The vaporized precursor stream created by the secondvaporizer 521 is provided to a chamber by-pass valve 570 that connects,via outlet 571, the vaporized gas stream to chamber assembly 200 viaprocess gas supply line 586. Alternatively, by-pass valve 570 canconnect the vaporized precursor stream to exhaust system 300 via outlet572. Temperature control methods described above are used to providetemperature controlled conduits to provide low vapor pressure precursorsto second vaporizer 521 and to convey vapor from vaporizer 521 toprocessing region 202. In addition, the components associated withsecond vaporizer 521 are equipped like the components associated withvaporizer 520 to heat the carrier gas and the vaporizedprecursor/carrier gas mixture.

Another object of the vapor delivery system 500 of the present inventionis the deposition of a variety of films on substrates 201 within processarea 202 by advantageously selecting precursors for bulk containers 503,504, process gases or carrier gases for gas source 579, and by selectivepositioning of by-pass valves 545 and 570. One advantage of the 2vaporizer—2 by-pass configuration of FIG. 17 is that each vaporizer maybe in operation and producing stable, repeatable flow that could beeasily ported to process region 202 or exhaust system 300 by aligningthe appropriate by-pass valve 545 or 570.

Referring now to FIG. 18, which is an alternative embodiment of aspectsof the liquid and vapor delivery systems of FIGS. 2-17, thisconfiguration of the invention employs the same functional relationshipsbetween the components as discussed with reference to FIGS. 2-17, but inan alternative layout where liquid flow meter 510 and vaporizer 520 arearranged horizontally relative to each other in a vaporizer box 502.

Now referring to FIG. 19, which is a schematic drawing of a secondrepresentative LDS and vapor delivery system with two vaporizers, thisembodiment includes a second vaporizer 521 and the correspondingcomponents (not shown) that supply vaporizer 521 with precursor fluid,solvent, and carrier gas as supplied to vaporizer 520, such as a secondliquid flow meter 510′, a second three-way inlet valve 588′, a secondcarrier gas supply line 532′, a second carrier gas heat exchanger 530′,and a second positive shut-off valve 522′. In this embodiment thevaporized precursor exits vaporizer 521 and flows through vaporizeroutlet conduit 543 directly into vaporizer outlet manifold 542. Thus,vaporized precursor from both vaporizers 520, 521 enters and is directedby by-pass valve 545 to either heated feed-through line 560 or by-passline 322.

Referring now to FIG. 20, which is an alternative embodiment of theliquid and vapor delivery systems of FIG. 19, this configuration of theinvention employs the same functional relationships between thecomponents as discussed with reference to FIG. 19. But in thisalternative layout liquid flow meters 510, 510′ and vaporizers 520, 521are arranged horizontally relative to each other in a vaporizer box 502,somewhat akin to the configuration of FIG. 18. Vaporizer box 502 withspill pan 514 encloses the vaporizers in a manner similar to LDS housing108 of FIG. 4. Vaporizer box 502 has slotted plates 111 that interactwith horizontal slots 112 that are shown about the interior base ofvaporizer box 502. House exhaust is attached through exhaust port 501(FIG. 12), drawing air through horizontal slots 112. Slotted plates 111adjust as discussed with reference to FIG. 4 to tune the vaporizer boxexhaust flow, although slotted plates 111 in FIG. 20 are modified to betuned in a side-to-side fashion. Optical switch 506 detects whether anyliquid is present in spill pan 514. Optical switch 506 is an interlockedhardware switch that de-energizes the gas and precursor control valvesas listed in Table I. Also, as part of the interlock system, a sensor(not shown) monitors airflow through exhaust port 501 (FIG. 12) via asensor port 516 (FIG. 12) and the system de-energizes the gas andprecursor control valves should the flow be too low, as listed below inTable I. Although it is not shown in FIG. 4, LDS housing 108 may also befitted with a spill pan and an interlocked optical switch in the mannerof vaporizer box 502.

FIG. 21 is a schematic of an embodiment of the present invention withtwo vaporizers mounted on the chamber lid. In this embodiment dualindependent temperature controlled vaporizers 520, 521 are mounted onchamber lid 205 along with many of the components of two vapor deliverysystems 500 to create a chamber lid/vaporizer assembly 800. Mountingvaporizer delivery systems 500 on the chamber lid 205 minimizes theheated path of the vaporized precursor materials from the point ofvaporization in vaporizers 520, 521 to processing region 202. Similarlynumbered elements function as discussed with reference to the earlierembodiments depicted in FIGS. 2-16.

Chamber lid/vaporizer assembly 800 also generally incorporates oxidizer(process) gas heater 582, carrier gas heat exchangers 530, 530′,three-way inlet valves 588, 588′, liquid flow meters 510, 510′, positiveshut off valves 522, 522′, vapor delivery manifolds 802, 803, unionblock 826, valve block 828, inlet and mixing block 830, liquid spilldetector 804 (FIG. 27), cover interlock switch 806 (FIG. 27), flexibledouble-contained liquid lines 700, 707, 708, and heated plasma manifold270.

Carrier gases from carrier sources 531, 531′ and process gas fromprocess gas source 579 enter chamber lid/vaporizer assembly 800 throughchamber lid 205 in the manner depicted in FIG. 10 with respect toprocess gas (elements 227/228). Briefly restated, these gases each passthrough a chamber feed-through 227, 815, 817 and lid bore-through 228,816, 818 for the process gas and carrier gases, respectively. O-ringsare used in the transitions from chamber bore-through to lidbore-through to maintain passageway integrity.

Process gas from source 579 is heated by process gas heater 582 andenters inlet and mixing block 830 (shown more clearly in FIG. 26).Carrier gas from source 531 is heated by carrier gas heat exchanger 530before entering vaporizer 520. Similarly, carrier gas from source 531′is heated by carrier gas heat exchanger 530′ before entering vaporizer521. Precursor from container 503 enters chamber lid assembly throughflexible double-contained liquid line 708, passes through three-wayinlet valve 588, liquid flow meter 510, and positive shut off valve 522,before entering vaporizer 520. Similarly, precursor from container 504enters chamber lid assembly through flexible double-contained liquidline 707, passes through three-way inlet valve 588′, liquid flow meter510′, and positive shut off valve 522′, before entering vaporizer 521.Solvent from container 589 enters chamber lid assembly through flexibledouble-contained liquid line 700 and flows through solvent delivery line591 to both three-way inlet valves 588, 588′. Thus, as with theembodiment depicted in FIG. 2, three-way inlet valves 588, 588′ maysupply either precursor liquid or a solvent to their respective liquidflow meters, with the solvent used to flush the system for maintenance.

Vaporizers 520, 521 are mounted to vapor delivery manifolds 802, 803respectively. In this embodiment, each liquid flow meter 510, 510′ alsoincludes a metering valve 524 (FIG. 15) and flow meters 510, 510′control precursor flow as described with reference to FIG. 15. Precursorliquid passes from positive shut-off valves 522, 522′ to vaporizers 520,521, respectively, which vaporize the liquid as discussed earlier withreference to FIGS. 2-16. Vaporizers 520, 521 then deliver the vapor tovapor delivery manifolds 802, 803, which in one embodiment have 0.500″diameter internal conduits 808. Delivery manifolds 802, 803 in turndeliver the vaporized precursor materials and carrier gas to commonconduit 810 within union block 826. Common conduit 810 conveys themerged precursor materials and carrier gas to by-pass valve 545 that iswithin valve block 828. By-pass valve 545 functions as described withreference to FIG. 10 and either conveys the vapor to by-pass line 322,or to common conduit 811 that lies within mixing block 830. Commonconduit 811 conveys the 2-precursor/carrier gas mixture to centralconduit 834.

In a further aspect of this invention, common conduit 811 directs flowtoward process gas inlet conduit 832 and process gas inlet conduit 832directs flow toward common conduit 811. Thus, the process gas injectionpoint of process gas inlet conduit 832 is opposed to common conduit 811across central conduit 834. This opposed flow causes turbulence thatensures good mixing of the process gas with the vaporized precursors.

Central conduit 834 directs the mixture of vaporized precursors andprocess gas through conduit 230 in lid 205 and the precursors and gaspass through blocker plate 237 and showerhead 240 on the way toprocessing region 202 as discussed with reference to the embodimentdepicted in FIG. 6.

Heated plasma manifold 270 is also connected to the mixing block 830 todeliver an activated species cleaning gas to processing region 202. Theactivated species, described earlier in FIG. 13, passes through chamberfeed-through 229 and lid bore-through 221 and within conduit 271 throughmanifold 270 and block 830 before merging with mixing conduit 834.

The embodiment depicted in FIG. 21 maximizes the advantages gained bydecreasing the distance from the vaporizer to the processing region, butfunctions generally as discussed with respect to FIGS. 2-18, as do theindividual components. Differences exist between this embodiment and theearlier embodiments in the flow path from the vaporizers to theprocessing region. Specifically, when vaporizers 520, 521 were discussedwith reference to FIGS. 2-18, each vaporizer directed vapor toindividual by-pass valves 545, 570. In the chamber lid/vaporizerassembly embodiment depicted in FIGS. 19, 20, 23, 24, 27, 28, and 29both vaporizers 520, 521 direct vapor to the same by-pass valve in themanner of the embodiment depicted in FIG. 19.

Also, in this embodiment, the pressure of each carrier gas is monitoredupstream of the vaporization frit (not shown) within vaporizers 520, 521using 100 Torr capacitance manometers (not shown). This allows thecarrier gas inlet pressure to be periodically checked to determine ifthe vaporization frit is becoming clogged or needs maintenance. FIG. 21also illustrates by dotted line the valves that are controlled byon-board software control module 1000. Although they are not illustratedin the earlier figures, similar connections from on-board softwarecontrol module 1000 to pedestal heater controllers, power supplies, andvarious system monitors (such as pressure transducers, exhaust flowmonitors, and pump signals) exist and facilitate the interlocks of TableI, below, and the automation of many aspects of the operation of thepresent invention.

FIG. 22 is a perspective view of an embodiment of the present inventionwith two vaporizers mounted on the chamber lid. The functionaldescription of FIG. 21 applies equally to FIG. 22. In this embodiment,delivery manifolds 802, 803, union block 826, valve block 828 (FIGS. 23,29) heated plasma manifold 270, and mixing block 830 are attacheddirectly to each other. O-rings maintain the integrity of the conduits808, 810, 811, 271 as they transition from one block to the next.

This view shows that delivery manifolds 802, 803 and union block 826 areindependently heated using heater cartridges, such as heater cartridge264. It is not shown, but valve block 828, mixing block 830, and heatedplasma manifold 270 are also similarly independently heated. In thisembodiment heater cartridges 264 are 208V cartridges of various powerratings. Each block has embedded thermocouples 204 for monitoring thetemperature and providing feedback to the temperature controllers. Eachmanifold and vaporizer section is independently controlled by separatetemperature controllers that allow each section to have differenttemperature set-points if needed as discussed with regard to theembodiment depicted in FIG. 2. The cartridge heater 264, thermocouple,and controller function was described in detail with reference to block262 and manifold 272 of FIG. 6. Again, for clarity, the separatethermocouples and controllers have been mostly omitted, but, in thisembodiment, these controllers work to independently control ninesections, are provided with over-temperature switches 209 (shown inmanifolds 802, 803), and are capable of heating up to 230° C. In anembodiment of the invention, delivery manifolds 802, 803, union block826, valve block 828, and mixing block 830 are heated to operate attemperatures of from 30° C. to 230° C. As part of the interlock system,over-temperature switches 209 switch off the related heater circuitshould the temperature go too high, as listed in Table I below. In anembodiment of the invention, there are six independently controlledsections between vaporizers 520, 521 and central lid bore-through 230.

In this embodiment of the invention, by-pass valve 545 (FIG. 21) isimplemented using a combination of two pneumatic on/off valves 546 (FIG.26), 547 (FIG. 27) that are controlled by on-board software controlmodule 1000 (FIG. 21). Both valves 546, 547 (FIG. 27) are normallyclosed. Valve 546 controls flow from common conduit 810 (FIG. 21) tocommon conduit 811 (FIG. 21). Valve 547 (FIG. 27) controls flow fromcommon conduit 810 to by-pass line 322 (FIG. 21). By-pass line 322 (notshown in FIG. 22 for clarity) is a flexible vacuum hose that exitschamber lid/vaporizer assembly 800 through a hole in a lid cover 822(FIG. 25) to eventually connect to chamber by-pass inlet 320 as depictedin FIG. 2. In this embodiment, three-way inlet valves 588, 588′ are eacha similar combination of two pneumatic on/off valves that are controlledby on-board software control module 1000 (FIG. 21).

With chamber lid/vaporizer assembly 800, precursor liquids and solventarrive through lid shelf 812 to precursor supply lines 508, 508′ andsolvent delivery line 591. Lid shelf 812 translates and rotates whenchamber lid 205 is opened. The apparatus for conveying precursor liquidsfrom bulk containers 503, 504, and solvent container 589 to chamberlid/vaporizer assembly 800 must accommodate this lid movement.

Now referring to FIG. 23, which is a cross-sectional view of anembodiment of the flexible double containment line of the presentinvention, flexible double-contained liquid lines 700, 707 (FIGS. 25),and 708 (FIG. 24) flex to accommodate the movement of lid shelf 812.Flexible double-contained liquid line 700 contains a primary line 702within a larger secondary line 704 and endcaps 710, 712. Secondary line704 also prevents material loss should primary line 702 develop a leak.Both primary line 702 and secondary line 704 are equipped with flexiblesections 703 and 705, respectively, that allow flexible double-containedliquid line 700 to bend. Volume 706 is defined by the space betweenprimary line 702, secondary line 704, the endcaps 710, 712, rigidprimary line 714, and rigid secondary line 716. Primary line 702 isconnected to rigid primary line 714 at connector 718. Rigid primary line714 extends through endcap 712 at hole 720, through LDS housing 108(FIG. 24), and is connected to a bulk storage container (not shown).Hole 720 is larger than rigid primary line 714 so that annular volume706 continues between rigid primary line 714 and endcap 712. Rigidsecondary line 716 is connected to endcap 712 about rigid primary line714 and houses rigid primary line 714 until line 714 passes through LDShousing 108. Where rigid primary line 714 enters LDS housing 108, theannular space between rigid secondary line 716 and rigid primary line714 is sealed. Thus, annular volume 706 extends through endcap 712,between rigid primary line 714 and rigid secondary line 716 to the pointwhere rigid secondary line 716 is sealed to rigid primary line 714.

Volume 706 is pressurized and monitored by a pressure monitor 701. Thepressure in volume 706 is adjusted to be higher than any attained withinprimary line 702 during processing. Therefore, if primary line 702develops a leak during processing, the pressure in volume 706 will drop.The liquid deposition system is interlocked to pressure monitor 701 sothat, should the monitor detect a pressure drop, the liquid depositionsystem and any other interlocked system will shut down, similar to theconditions indicated by Table I for a LDS spill below. A typicalpressure in volume 706 is about 60 p.s.i. In one embodiment, primaryflexible section 703 is 0.125″ O.D. (0.055″ I.D.) line, rigid primaryline has a 0.125″ O.D., and rigid secondary line has a 0.25″ O.D.Flexible double-contained liquid lines 707, 708 (FIG. 22) have the sameconstruction as line 700.

Referring now to FIG. 25, which is a perspective view of an embodimentof the present invention with two vaporizers mounted on the chamber lidwith the chamber lid/vaporizer assembly in the open position, flexibledouble-contained liquid lines 700, 707 are flexed because chamberlid/vaporizer assembly 800 is in the open position. The entire chamberlid/vaporizer assembly 800 is enclosed by an exhausted lid cover 822(depicted translucently) that is designed to properly exhaust escapedgas and liquid to the foreline system. Lid cover 822 is larger than theprevious cover 203 (FIG. 3) to accommodate the elements of two vaporizersystems. Both lid cover 822 and spill rail 824 cooperate to preventoperator exposure to hazardous or hot materials.

Now referring to FIG. 26, which is a second perspective view of anembodiment of the present invention with two vaporizers mounted on thechamber lid, oxidizer gas enters mixing block 830 from the side oppositefrom vaporizers 520, 521 and on/off valve 546. Also, in this figure,mixing block 830 has been arbitrarily divided into an upper mixing block830A and a lower mixing block 830B for descriptive purposes. In thisembodiment process gas enters upper mixing block 830A via process gassupply line 586 and process gas inlet conduit 832 (FIG. 21). Vaporizedprecursor enters upper mixing block 830A via common conduit 811 (FIG.21). Plasma enters lower mixing block 830B through heated plasmamanifold 270 and activated species conduit 271 (FIG. 21).

Advancing to FIG. 27, which is a third perspective view of an embodimentof the present invention with two vaporizers mounted on the chamber lid,aspects of the embodiment of chamber lid/vaporizer assembly 800 appearmore clearly. Chamber lid 205 is designed with a spill rail 824 thatcaptures and contains a liquid spill when chamber lid 205 is horizontal.Chamber lid/vaporizer assembly 800 is also equipped with liquid spilldetector 804 and cover interlock switch 806. Spill detector 804 andcover interlock switch 806 are hardware switches that cause parts of thesystem to stop functioning as described in the “result” column of TableI should their status meet the criteria described in the “trip cause”column. Additionally, FIG. 27 further illustrates the relativepositioning of vaporizers 520, 521, on/off valve 547, and valve block828 above heated plasma manifold 270.

Many systems associated with chamber assembly 100 are interlocked. Aninterlock may be a hardware switch, or part of on-board software controlsystem 1000 (FIG. 21) that, when activated or “tripped,” prevents thecontinued operation of the interlocked system. A condition thatactivates an interlock is, thus, known as a “trip cause.” Interlockedchamber assembly systems generally stop power to the heaters and preventgas flows when the interlock is tripped. Most interlocks are designed sothat the trip causes (which may be hard-wired circuits or softwaresignals) are connected in series with the interlocked system. When anyone of the trip causes in the series occurs, the interlocked system willbe de-activated. One embodiment of the invention employs a series ofelectrical relays as interlocks, where a trip cause with opens anindividual relay and stops power to the system. The interlocked systemsof chamber assembly 100 are listed in the Result column of Table I whichalso contains the interlock name, trip cause, and whether the system isshut down via a hardware switch or software control. For example,chamber lid 205 is fitted with a position detector (not shown) thatmonitors the position of chamber lid 205 relative to chamber body 210.This position detector is normally open, and completes a circuit whenlid 205 is closed. Chamber lid 205 is also interlocked so that it willnot open if the pressure within processing region 202 is above 10 Torr.As listed in Table I, the systems that introduce material intoprocessing region 202 or that heat processing region 202 are interlockedto the position detector and the pressure detector.

TABLE I Interlock Trip Cause Result Hardware or Software Chamber LidOpen chamber lid Gas valves, heaters, Hardware Switch chamberde-energized Over Chamber over pressure Gas valves, heaters, Pressuretransducer Pressure chamber de-energized monitored by software andHardware Switch H₂O Flow Low H₂O flow at one of the Water heater andmulti loop Hardware relay control Low Flow cooling loops heatercontroller power de- energized Liquid Leak Detector Action Opticalswitch in spill pan Gas and precursor valves Hardware switchde-energized Roughing Pump OK Loss of OK signal from Gas, precursorvalves and Hardware switch pump heater de-energized Liquid DeliverySystem Loss of ventilation to LDS Gas and precursor valves Hardwareswitch (LDS) Exhaust in LDS and vaporizer de- energized LDS Spill Leakdetected in LDS spill Gas and precursor valves Hardware switch pan inLDS and vaporizer de- energized LDS Magnetic proximity switch Gas andprecursor valves Hardware switch Door on door is open de-energizedVaporizer Leak detected in LDS spill Gas and precursor valves Hardwareswitch Spill pan de-energized Vaporizer Exhaust Loss of ventilation toGas and precursor valves Hardware switch vaporizer de-energizedOver-Temp Switch Thermal control failure Snap switch opens supplyHardware switch line to heater blanket

It is a further aspect of the invention that the chamber assembly ispartly automated by on-board software control module 1000. Referring toFIG. 28, which is a flow chart illustrating automation of the processingsystem according to an embodiment of the invention, sub-systems ofprocessing system 100 send input 1002 to control module 1000. Software1006 receives the input at step 1008, analyzes the input at step 1010,commands the appropriate elements of the sub-system(s) at step 1012 toperform responsive procedures by sending orders 1004, and notifies theuser at step 1014 through a display (not shown) associated with controlmodule 1000.

In one embodiment, software 1006 controls aspects of the gas and vapordelivery systems during system maintenance. For example, when systemoperators need to change a near-empty bulk storage container 503, 504(FIGS. 14, 16, and 17) for a full container, gauges (not shown) in thebulk storage containers provide input 1002 to on-board software controlmodule 1000 that a storage container is near empty. Software 1006receives the input at step 1008 from the gauges, analyzes the input atstep 1010, and commands the sub-system at step 1012, in this case vapordelivery system 500, to perform procedures that are associated withchanging a bulk container. In this instance, when the bulk storagecontainers are empty, orders 1004 will stop power to the processingsystem.

Software 1006 is also employed during maintenance to run sub-routinescalled for by steps in the maintenance manual for processing system 100.In this manner, software 1006 receives directions from the operator asinput at step 1008, as well as input from the processing systems 100.For example, software 1006 may be directed to run sub-routines thatdirect the sub-systems of processing system 100 to perform these otherfunctions as well: 1) relieving pressure in the bulk storage containers503, 504; 2) evacuating solvent delivery line 591; 3) Evacuating andre-charging the lines down stream of three-way inlet valves 588, 588′after a liquid flow meter or vaporizer component change; 4) purgingprecursor liquid lines from near the bulk storage containers 503, 504 toby-pass valve 545; 5) flushing solvent deliver line 591 with solvent andhelium after a precursor bulk storage container change; 6) evacuatingprecursor liquid supply lines from precursor bulk storage container toby-pass valve 545; 7) charging precursor delivery supply lines betweenprecursor bulk storage container and chamber with precursor; 8) flushingliquid flow meters 510, 510′ and vaporizers 520, 521 with solvent; 9)purging liquid flow meters 510, 510′ and vaporizers 520, 521 withhelium; 10) flushing the lines from bulk storage supply containers toliquid flow meters with solvent and pumping them down; 11) relieving thepressure in the solvent bulk storage container; 12) evacuating solventdelivery line 591 for bulk storage container change; and 13) chargingprecursor supply lines 508, 508′ after changing bulk storage containers.

Also, on-board computer control module 1000 and software 1006 are partof the interlock that commands a sub-system to shut down in case of asystem overpressure and the interlock that commands a sub-system to shutdown in case of the loss of the roughing pump OK signal, as listed inTable I.

It is to be understood that while illustrative embodiments of theinvention have been shown and described herein, various changes andadaptions in accordance with the teachings of the invention will beapparent to those of ordinary skill in the art. Such changes andadaptions nevertheless are included within the spirit and scope of theinvention as defined in the following claims.

What is claimed:
 1. An apparatus for depositing a film, the apparatuscomprising: a chamber body having a processing region defined therein; avaporizer; a vapor delivery system having a first region beginning atthe vaporizer, a second region communicating with the processing regionand a third region disposed between the first and second regions,wherein the first region is maintained at a lower temperature than thesecond region; and a chamber lid disposed on the chamber body and havinginner and outer temperature control regions.
 2. The apparatus of claim1, wherein a temperature gradient defined over the first and secondregions is between about 20 to about 25 degrees Celsius.
 3. Theapparatus of claim 1, wherein the first vapor path further comprises: acarrier gas supply line is coupled to the first vapor path at atransition between the first and third regions.
 4. The apparatus ofclaim 1, wherein a diameter of the third region is greater than adiameter of the first region and less than a diameter of the secondregion.
 5. The apparatus of claim 1, wherein a temperature of the thirdregion is greater than a temperature of the first region and less than atemperature of the second region.
 6. The apparatus of claim 1 furthercomprising: a hafnium precursor source coupled to the vaporizer.
 7. Theapparatus of claim 6, wherein the temperature gradient is maintainedbetween a minimum temperature of 100 degrees Celsius and a maximumtemperature of 190 degrees Celsius.
 8. An apparatus for depositing afilm, the apparatus comprising: a chamber body having a processingregion defined therein; a vaporizer; a vapor delivery system having afirst region beginning at the vaporizer, a second region communicatingwith the processing region and a third region disposed between the firstand second regions, a diameter of the third region being greater than adiameter of the first region and less than a diameter of the secondregion; and a chamber lid disposed on the chamber body and having innerand outer temperature control regions.
 9. The apparatus of claim 8, acarrier gas supply line is coupled to the first vapor path at atransition between the first and third regions.
 10. The apparatus ofclaim 8, wherein the first vapor path further comprises: wherein atemperature gradient defined over the first and second regions isbetween about 20 to about 25 degrees Celsius.
 11. The apparatus of claim8, wherein a temperature of the third region is greater than atemperature of the first region and less than a temperature of thesecond region.
 12. The apparatus of claim 8 further comprising: ahafnium precursor source coupled to the vaporizer.
 13. The apparatus ofclaim 12, wherein the temperature gradient is maintained between aminimum temperature of 100 degrees Celsius and a maximum temperature of190 degrees Celsius.